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  • 42.75
  • Aircraft Propulsion and Power
  • Pflanzenschädling
  • ddc:551.7
  • 1965-1969  (38)
  • 1955-1959  (72)
  • 1950-1954  (80)
Collection
Publisher
Language
Years
Year
  • 1
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    In:  Pflanzenschutznachrichten 'Bayer' 18, Sonderheft:138-217.
    Publication Date: 1965
    Description: Auswertung von 25jährigen Beobachtungen zur Beziehung von Klima, Obstbau und Pflanzenschutz, klimatische Voraussetzungen für den Obstbau anhand der Vegetationszeit, der frostfreien Periode, der Blütenphänologie und der Temperatursummen KATASTER-BESCHREIBUNG: Beziehung Blütenphänologie und Spinnmilben-Schlüpfbeginn, Zusammenhang Niederschlag und Ascosporenflug (Apfelschorf) KATASTER-DETAIL: Temperatursumme ~450°C (+-8.9%)von Jahresbeginn, dann Schlüpfbeginn der Spinnmilben Nied (Gesamtzahl der Niederschlagstage 〉45 bis zum 1. Juni), dann höchste Anzahl der Infektionen vom 1. Ascosporenflug bis 15.6. und bis Ernte
    Keywords: Versuchsgut Höfchen, Nordrhein-Westfalen ; 1940-1964 ; Insekten ; Ertrag ; Forst ; Klima ; Niederschlag ; Pflanzenkrankheit ; Pflanzenschädling ; Temperatur ; Obst
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  • 2
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    In:  Gesunde Pflanzen 6; p.166-168
    Publication Date: 1954
    Description: Der Autor erklärt das massenhafte Auftreten verschiedener Blattlausarten Ende Mai 1954 mit trockenem warmem Wetter und nennt 19°C Tagesmitteltemperatur und Schwachwindigkeit als Fluginitiator für die Blattläuse. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Berlin, Hannover, Bonn ; 1954 ; Pflanzenschädling ; Witterung
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  • 3
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    In:  Nachrichtenblatt des deutschen Pflanzenschutzdienstes 5, Nr.10; p.145-150
    Publication Date: 1953
    Description: Der Autor untersuchte die für das Auftreten des weißen Bärenspinners günstigen Temperaturen im ehemaligen Jugoslawien (Palic, Vojvodina) und Österreich (Burgenland) und identifizierte die Temperaturen von Mai bis August als wichtige Einflußfaktoren auf die Entwicklungszeit des Falters. Hierdurch konnten Temperaturen identifiziert werden bei denen eine, zwei oder sogar drei Generationen im Jahresverlauf vorkommen können. Sobald die Temperaturen 14-15°C überschreiten, kann die Entwicklung der ersten Generation beginnen. Die gewonnenen Erkenntnisse wurden dazu eingesetzt, um das Ausbreitungspotential des Schmetterlings aufgrund klimatischer Parameter nach Mitteleuropa abzuschätzen. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Jugoslawien, Österreich, Deutschland ; 1946-1952 ; Pflanzenschädling ; Temperatur
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  • 4
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    In:  Mitt. Biol. Bundesanst. Land-Forstwirtsch. Berlin-Dahlem; p.23-27
    Publication Date: 1956
    Description: Der Autor beschreibt Versuche, bei denen der Einfluß von Temperatur, Feuchte und Luftdruck auf das Häutungsverhalten von Blattläusen (Aphiden), sowie der Einfluß von Windgeschwindigkeiten und ihrer Gleichmäßigkeit auf das Flugverhalten von Blattläusen untersucht wurden. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: England, Rothamsted, Labor ; 1954-1955 ; Pflanzenschädling ; Temperatur ; Wind
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  • 5
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    In:  Arch. Gartenbau 4, Heft 4; p.277-278
    Publication Date: 1956
    Description: Auf der Basis von Messungen mit Apfelwicklerkontrollkästen wurden unter anderem anhand von Korrelationsanalysen der Einfluß der Temperatur auf das Schlüpfen des Apfelwicklers, sowie den Apfelwicklerflug untersucht. Als Ergebnis wird unter anderem eine Temperatursummenregel präsentiert. KATASTER-BESCHREIBUNG: Temperatursummenregel für den Massenflug der ersten Apfelwicklergeneration im Jahr. KATASTER-DETAIL: Mit dem Beginn des Massenfluges der ersten Generation ist zu rechnen, wenn ab einer Temperatursumme von 283°C (Basis 6°C) ab Huflattichblüte bzw. 136°C (Basis 8°C) ab Stachelbeerblüte niederschlags- und windarme Tage mit Tagesmitteltemperaturen 〉=15°C auftreten.
    Keywords: DDR ; 1953-1955 ; Apfel ; Pflanzenschädling ; Obst
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  • 6
    Publication Date: 1952
    Description: Vergleich des täglichen Flugverhaltens der Aphiden Doralis fabae und Myzodes persicae (Zweigipfelige Kurve) mit der Psyllide Trioza nigricornis (Eingipfelige Kurve). Die Prozentuale Verteilung der Blattläuse auf verschiedene Flughöhen wird analysiert. Die Abhängigkeit des Flugverhaltens der Blattläuse von den Faktoren Licht, Wind,Temperatur, relative Luftfeuchte wird untersucht. Zudem wird deren kombinierte Wirkung auf den Flug der Homopteren untersucht und im Zuge dessen die drei Homopteren in drei verschiedene Reaktionstypen eingeordnet. KATASTER-BESCHREIBUNG: Grenzwert der Windgeschwindigkeit für den aktiven Abflug von Aphidae und Psyllidae. Regressionsgleichungen für den Zusammenhang zwischen Temperatur und Flugtätigkeit der beiden Aphidae (T(200)=Temperatur in 2m Höhe; T(10)=Temperatur in 10 cm Höhe); Multipler Korrel.koeff. zwischen Temp., modif. rel. Luftf. und dem aktiven Anflug von Trioza nigricornis R=0,742; Zusammenhang der Flugtätigkeit von T. nigricornis und Temp, ist linear -〉 siehe Korrelationstabelle KATASTER-DETAIL: Wind 〉3km/h dann aktiver Abflug Aphiden = 0; Delta T (2m;〈18,46°C) + oder Delta T (2m;〉18,46°C) - oder Delta T (10cm;〈17,18°C) + oder Delta T (10cm;〉17,18°C) - dann Flugtätigkeit M.persicae + ;Delta T (2m;〈19,32°C) + oder Delta T (2m;〉19,32°C) - oder Delta T (10cm;〈19,5°C) + oder Delta T (10cm;〉19,5°C) - dann Flugtätigkeit D.fabae + ;Delta T + und Delta relf (bis 60-70%) - dann Anflug T.nigricornis + Regressionsgleichungen für Myzodes persicae: Flugtätigkeit(FT)=-136,19 + 16,61*T(200) - 0,45*T(200)²; FT=-95,62 + 13,74*T(10) - 0,40*T(10)²; Regressionsgleichungen für Doralis fabae: FT=-62,56 + 8,075*T(200) - 0,209*T(200)²; FT=-93,29 + 11,193*T(10) - 0,287*T(10)²;
    Keywords: Quedlinburg, Thüringen ; 1951 ; Tabak ; Getreide ; Pflanzenschädling ; Hackfrüchte ; Obst ; Zierpflanzen ; Gemüse
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  • 7
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst 12, Heft 11; p.201-209
    Publication Date: 1958
    Description: Der Autor fasst Informationen über Schadbild, Entwicklung, Bekämpfung und natürliche Feinde aus der Literatur zusammen und vergleicht diese teilweise mit eigenen Beobachtungen. Auch der Einfluß klimatischer Parameter wird zum Teil beleuchtet. So wurde bei der Temperatur 4°C als Minimum und 32°C als Optimum und bei der rel.Luftfeuchtigkeit 86% als Minimum der Embryonalentwicklung ermittelt. Für eine kontinuierliche Larvenentwicklung wurden 12°C als Minimum und 28°C als Optimum (6-7 Tage Entw.zeit) ermittelt. Epidemischer Befall und sehr gute Generationenfolge ist ab erreichen von 470 Wärmeeinheiten bzw. warme, nicht zu trockene Witterung mit 15-20°C in den Sommermonaten zu erwarten. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: DDR ; 1958 ; Mais ; Pflanzenschädling
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  • 8
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    In:  Ratgeber Obst-, Gartenbau, Geflügelzucht, Heft 5, p. 102-103
    Publication Date: 1951
    Description: Beschreibung der Faktoren für Lebenslauf und Massenvermehrung sowie Ratschläge zur Bekämpfung des Apfelwicklers mittels Spritzungen KATASTER-BESCHREIBUNG: Zusammenhang zwischen Entwicklung des Apfelwicklers in seinen Stadien und der Temperatur sowie der Feuchtigkeit KATASTER-DETAIL: Delta T: Tmin 〈 10°C, dann keine Entwicklung von Ei und Raupe möglich; T 〈 11°C, dann keine Entwicklung von Puppe möglich; Delta T +, dann Einbohren in den Apfel +; T〈15°C, dann kein Einbohren möglich; Tmit(Dekade)〉15°C, dann Flugbeginn; Delta Nied (Mai+Juni)-, dann Apfelwickler +
    Keywords: Bayern ; 1950 ; Pflanzenschädling ; Temperatur ; Obst
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  • 9
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    In:  Prakt. Bl. Pflanzenbau Pflanzenschutz, p. 103-108
    Publication Date: 1956
    Description: Allgemeiner Bericht über die Lebensweise der Bohnenfliege und deren Bekämpfung KATASTER-BESCHREIBUNG: Einfluss der Temperatur auf die Entwicklung der Bohnenfliege KATASTER-DETAIL: T 〉= 10°C, dann Schlüpfen; Delta T +, dann t (Puppenruhe) -;
    Keywords: Deutschland ; 1950-55 ; Pflanzenschädling ; Temperatur ; Gemüse
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  • 10
    Publication Date: 1954
    Description: Bericht über Untersuchungen zur Terminwahl für die Bekämpfung von Kohlschotenrüßler und Kohlschotengallmücke sowie Vergleiche der Ergebnisse mit der bisherigen Literatur KATASTER-BESCHREIBUNG: Einfluss der Temperatur auf das Auftreten des Kohlschotenrüßlers KATASTER-DETAIL: Delta T +: Tmit 〉 15°C, dann Erscheinen des Kohlschotenrüßlers
    Keywords: Sachsen-Anhalt ; 1952-1953 ; Pflanzenschädling ; Temperatur ; Raps
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  • 11
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    In:  Anz. Schädlingskunde 26, p. 49-51
    Publication Date: 1953
    Description: Untersuchungen zum durch Spinnmilben (Tetranychus althaeae v. hanst.) an Zuckerrüben verursachten Schadbild je nach der Befallsintensität KATASTER-BESCHREIBUNG: - KATASTER-DETAIL: -
    Keywords: Diendorf, Österreich ; 1952 ; Zuckerrüben ; Pflanzenschädling
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  • 12
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    In:  Mitteilungen aus der Biologischen Zentralanstalt für Land- und Forstwirtschaft, Berlin-Dahlem, Heft 69
    Publication Date: 1950
    Description: Bericht über die Ergebnisse der Untersuchungen zu den Wechselwirkungen zwischen Larve und Wirtspflanze KATASTER-BESCHREIBUNG: Einfluss der Temperatur auf den Larvenbefall KATASTER-DETAIL: Delta T -, dann Entwicklungsdauer der Larven +; T 〉 0°C, dann Froststarre und Wanderfähigkeit -; Delta T - und Delta Relf +, dann Larvenmortalität +
    Keywords: Berlin-Dahlem ; 1948-1949 ; Insekten ; Luftfeuchte ; Pflanzenschädling ; Temperatur ; Raps
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  • 13
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    In:  32. Deutsche Pflanzenschutztagung der Biologischen Bundesanstalt für Land- und Forstwirtschaft in Hannover, 6.-10. Oktober 1958; Mitt. Biol. Bundesanst. Land-Forstwirtsch. Berlin-Dahlem 97, p. 181-188
    Publication Date: 1959
    Description: Untersuchungen zu den Bedingungen für das Verlassen des Bodens und somit den Beginn des Zufluges um eine optimale Bekämpfung zu ermöglichen KATASTER-BESCHREIBUNG: Einfluss der Temperatur auf die Aktivität von Gallmücken KATASTER-DETAIL: T (Boden, 2cm) 〉 20°C, dann Verlassen des Bodens; Tmax (Luft) 〉 16°C, dann Gallmücken flugaktiv
    Keywords: Aschersleben und Seggerde ; 1955-1958 ; Boden ; Pflanzenschädling ; Temperatur ; Weizen ; Witterung
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  • 14
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    In:  Informationen der Hauptstelle für Forstlichen Pflanzenschutz (Eberswalde); Nr. 6.
    Publication Date: 1969
    Description: Informationen zur Vermehrung der Kiefernbestandesschädlinge und deren Fraßschäden KATASTER-BESCHREIBUNG: Einfluss der Witterung auf die Schädlingspopulation: extreme Sommerwitterung führt zum Anstieg der Schädlingspopulation in den folgenden Jahren KATASTER-DETAIL:
    Keywords: DDR ; 1969 ; Forst ; Pflanzenschädling ; Sturmschaden ; Temperatur ; Trockenheit ; Witterungsextreme
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  • 15
    Publication Date: 1959
    Description: Mit Hilfe von Aufzuchtversuchen in Aufzuchtzylindern, der Analyse eigener Beobachtungen und der Analyse von Berichten des Meldedienstes im Zeitraum 1953-1957 sucht der Autor nach Zusammenhängen zwischen dem Auftreten der Kohldrehherzmücke und klimatischen Parametern. Im Zuge der Analysen wird als Modell für die Entwicklung des Schaderregers bzw. für die Ermittlung des ersten Schlupftermins im Jahr ein Schwellenwert berechnet. KATASTER-BESCHREIBUNG: Prognose des ersten Schlüpftermins der Kohldrehherzmücke im Jahr mittels einer Temperatursummenregel KATASTER-DETAIL: C=(Temperatursumme von t1-t2)-(Anzahl aufsummierter Tage*Schwellwert) mit den vorher im Versuch bestimmten Werten C(Temperaturkonstante)=160 und Schwellwert(Temperaturnullpunkt)=7,2°C
    Keywords: DDR ; 1953-1957 ; Insekten ; Pflanzenschädling ; Temperatur ; Kohl
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  • 16
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    In:  Nachrichtenblatt des deutschen Pflanzenschutzdienstes 2.Jahrg., Nr.11; p.161-165
    Publication Date: 1950
    Description: In Freilandversuchen wurden Temperaturen ermittelt, bei denen Kartoffelkäfer den Boden im Frühjahr verlassen. Zudem wurden Minimalwerte für das Überleben in verschiedenen Bodenarten ermittelt. KATASTER-BESCHREIBUNG: Ein kritischer Wert der Bodentemperatur wurde für das massenhafte Verlassen des Bodens durch den Kartoffelkäfer ermittelt. Allerdings wurden auch bei 12,5°C Bodentemperatur bereits Kartoffelkäfer an der Oberfläche beobachtet. KATASTER-DETAIL: Kritischer Wert= 16,6°C Bodentemperatur (in 50cm Tiefe)
    Keywords: Heidelberg ; 1949-1950 ; Kartoffeln ; Pflanzenschädling ; Hackfrüchte
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  • 17
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    In:  Mitteilungen aus der Biologischen Zentralanstalt für Land- und Forstwirtschaft Berlin-Dahlem, Heft 73
    Publication Date: 1952
    Description: 4-jährige Feldexperimente und -beobachtungen zum winterlichen Massenwechsel der grünen Pfirsichblattlaus KATASTER-BESCHREIBUNG: Entscheidende Faktoren für Vorkommen und Ausmaß der anholozyklischen Überwinterung KATASTER-DETAIL: Delta T-: T(Bodennähe)〈= -5°C, dann Myzodes persicae -; Winterfröste: Dauer + , zeitiger, Minimum -, dann Myzodes persicae -; Nachwinter: Delta T + und Delta Nied -, dann Myzodes persicae +
    Keywords: Kölner Bucht ; 1948 - 1951 ; Pflanzenschädling ; Temperatur
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  • 18
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    In:  Nachrichtenblatt deutsch. Pflanzenschutzdienst, p. 123-128
    Publication Date: 1956
    Description: Ergebnisse zu Untersuchungen über die Entwicklung der Kohlschoten-Gallmücke unter Berücksichtigung der jeweiligen Witterungsbedingungen, Methoden der Befallsvorhersage und Versuche mit Kontaktinsektiziden zur Bekämpfung der Imagines KATASTER-BESCHREIBUNG: Einfluss der Witterung (Luftfeuchte und Temperaturschwankungen) auf den Massenflug KATASTER-DETAIL: Delta Relf + bzw. Delta Nied +, dann Massenflug +; Delta Nied +, dann Verpuppung + und Schlüpfen +;
    Keywords: Sachsen-Anhalt ; 1952-1953 ; Luftfeuchte ; Niederschlag ; Pflanzenschädling ; Temperatur ; Witterung
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  • 19
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    In:  Beiträge zur Entomologie, Band 3, p. 518-529
    Publication Date: 1953
    Description: Untersuchungen zum Ausbleiben des erwarteten starken Befalls im Herbst 1952 und Vergleich mit bereits veröffentlichten Erkenntnissen zum Massenwechsel des Rapserdflohs; KATASTER-BESCHREIBUNG: Abhängigkeit des Massenwechsels des Rapserdflohs von der Witterung (Temperatur) KATASTER-DETAIL: Delta T -: Delta T (August, September) -, dann Zuwanderung der Rapserdflöhe -;
    Keywords: Sachsen-Anhalt ; 1951-1953 ; Pflanzenschädling ; Temperatur ; Witterung ; Raps
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  • 20
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    In:  Gesunde Pflanzen 4, Heft 10; p.274-277
    Publication Date: 1952
    Description: Eine kurze Zusammenfassung der Einsparungen durch nicht benötigte Traubenwickler- und Peronosporabekämpfungen in der Pfalz im Jahre 1952 wird gegeben. Hierfür werden große Hitze und Trockenheit im Jahre 1952 im Vergleich zum Vorjahr und zum 31-jährigen Mittel als Ursache genannt. Die Prognose wurde durch Beobachtungen erstellt. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Pfalz ; 1951-1952 ; Pflanzenkrankheit ; Pflanzenschädling ; Wein
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  • 21
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    In:  Neue Mitt. Landwirtsch. 6, Nr.9; p.139-140
    Publication Date: 1951
    Description: Der Autor entwickelt ein Temperatursummenmodell zur Vorhersage der Kopula des Apfelblütenstechers. KATASTER-BESCHREIBUNG: Temperatursummenmodell zur Vorhersage der Kopula des Apfelblütenstechers KATASTER-DETAIL: Kopula tritt ab einer Temperatursumme (aufsummierte Stundenwerte) von 900-1000°C bei einer Basis von 8°C auf.
    Keywords: Hessen, Dippelshof ; 1948-1950 ; Apfel ; Pflanzenschädling ; Temperatur
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  • 22
    Publication Date: 1958
    Description: Der Autor beschreibt den Einfluß von Feuchtigkeit und Temperatur im Boden und der Luft auf verschiedene Entwicklungsabschnitte der Maulwurfsgrille. Neben beschreibenden Beobachtungen im Feld wurden auch Kardinalwerte im Labor erhoben. Die Optimaltemperatur liegt bei ausreichender Feuchtigkeit bei 25-35°C. Das Entwicklungsmaximum liegt bei rel.Luftfeuchte 95-100% bei ca.43°C. Das Entwicklungsminimum liegt bei 0°C Bodentemperatur, wobei die Lufttemperatur niedriger sein kann, da sich die Insekten dann in den Boden zurückziehen. Die Haupteinflußfaktoren auf die Entwicklung bzw. das Überleben der Maulwurfsgrille sind Kannibalismus, Temperatur, Feuchtigkeit und Feinde. Diese modifizieren das Schlupfergebnis von 50-60% bis zu 95-100%. Ein Vergleich zwischen Bedingungen in Brandenburg und Südeuropa wird gezogen. KATASTER-BESCHREIBUNG: Einfluß von Feuchte und Temperatur auf den Entwicklungszyklus im Allgemeinen und die Eizeit im Speziellen. KATASTER-DETAIL: Die Eizeit schwankt zwischen 2-4 Wochen, kann aber bei hoher Luftfeuchtigkeit und einer Bodentemperatur von 22-28°C (Lufttemp.30°C) auf 10 Tage sinken. Bei spät gelegten Eiern (Ende Sept.-Okt.), hoher Bodenfeuchte und Bodentemp. 15-17°C steigt die Eizeit auf 5-6 Wochen. Je wärmer der Sommer und je milder der Winter, desto kürzer ist der Entwicklungszyklus (bei günstigen Bedingungen 1 Jahr, bei schlechteren 2 Jahre).
    Keywords: Brandenburg ; Tabak ; Forst ; Getreide ; Landwirtschaft ; Pflanzenschädling ; Hackfrüchte ; Obst ; Zierpflanzen ; Gemüse
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  • 23
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    In:  Der Obstanbau, p. 184-185
    Publication Date: 1953
    Description: Beobachtungen zur Masseneinablage und zur Witterung KATASTER-BESCHREIBUNG: Zusammenhang zischen der Luftfeuchtigkeit und dem Flug sowie der Eiablage des Apfelwicklers KATASTER-DETAIL: Delta Relf (Trockenperioden) +, dann Flug + und Eiablage +
    Keywords: Deutschland ; 1952 ; Pflanzenschädling ; Trockenheit
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  • 24
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    In:  Zeitschrift für Pflanzenbau und Pflanzenschutz, p. 241-266
    Publication Date: 1950
    Description: Untersuchungen zur Verbreitung und zum Massenwechsel der grünen Pfirsichblattlaus hinsichtlich der Faktoren Wind und Thermik KATASTER-BESCHREIBUNG: Zusammenhang zwischen Massenvermehrung der Laus und Morphologie sowie meteorologischen Verhältnissen der Landschaft KATASTER-DETAIL: Wind +, dann Pfirsichblattlaus Wanderung +; Wind +, dann Strecke +; Sonneneinstrahlung +, dann Ausbreitung +; Nied +, dann Ausbreitung -;
    Keywords: Bayern ; 1950 ; Insekten ; Pflanzenschädling ; Wind ; Witterung
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  • 25
    Publication Date: 1950
    Description: Untersuchungen zur Schlüpfzeit, der Generationszahl und der Abflugzeiten von Myzodes persicae Sulzer am Pfirsichbaum KATASTER-BESCHREIBUNG: Zusammenhang zwischen Klima, Witterung und Schlüpfablauf von Myzodes persicae KATASTER-DETAIL: Delta T -, dann Verzögerung im Schlüpfablauf
    Keywords: Bonn ; 1947-1950 ; Kartoffeln ; Pflanzenschädling ; Temperatur
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  • 26
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst, p. 27-32
    Publication Date: 1957
    Description: Untersuchung des Flugverhaltens des Blattwicklers mit einer Ultraviolett-Lichtfalle bezüglich täglichen Flugbeginns, Falterzahl und Auftreten der Generationen sowie der Einflüsse von Temperatur, Niederschlag und Wind auf den Flug KATASTER-BESCHREIBUNG: Zusammenhang zwischen Flugverhalten und den Faktoren Temperatur, Niederschlag und Wind KATASTER-DETAIL: Delta Nied +, dann Flug -; Delta Nied (Tag) +, dann Flug (Nacht) -; vor Gewitter, dann Flug +; Delta Wind - und Delta T +, dann Flug +; Wind 〉 6 Windstärken, dann kein Flug; T〈 13°C, dann kein Flug; T〉=18°C, dann höchste Fangergebnisse
    Keywords: Deutschland ; 1955 ; Niederschlag ; Pflanzenschädling ; Temperatur ; Wind
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  • 27
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    In:  Natur und Volk, Bericht der Senckenbergischen Naturforschenden Gesellschaft, Band 85, Heft 3, p. 65-70
    Publication Date: 1955
    Description: Beobachtungen zum Auftreten der Made der Mittelmeerfrucht-Fliege nach unterschiedlich starken Wintern KATASTER-BESCHREIBUNG: Zusammenhang zwischen dem Auftreten der Made und der Temperatur im Winter KATASTER-DETAIL: Delta T (Sommer) -, dann Anzahl - T (Luft)〉= -15,4°C oder T (Boden) 〉= -12,2°C, Mittelmeerfruchtfliege als Puppe im Boden noch vital
    Keywords: Frankfurt am Main ; 1937 - 1953 ; Pfirsich ; Pflanzenschädling ; Temperatur
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  • 28
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst Neue Folge, p. 143-150
    Publication Date: 1958
    Description: Untersuchungen des Schlupfverlaufs zur Ermittlung von Bedingungen, unter welchen mit einem verstärkten Auftreten der 2. Generation zu rechnen ist. KATASTER-BESCHREIBUNG: Regulation der Stärke der 2. Generation durch die während der Larvenentwicklung herrschenden Temperatur- und Lichtverhältnisse KATASTER-DETAIL: Delta Tmit (Monat) +, dann Schlüpftermin früher; Tmax 〈14°C, dann Anzahl schlüpfender Falter - bis 0;
    Keywords: Labor ; 1953-1957 ; Apfel ; Pflanzenschädling ; Temperatur
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  • 29
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    In:  Höfchen-Briefe, Jahrgang 12, Heft 3, p. 111-140
    Publication Date: 1959
    Description: Erkenntnisse über die Art des sommerlichen Entwicklungsablaufes und der Freilandüberwinterung der Mittelmeerfruchtfliege in Mitteleuropa KATASTER-BESCHREIBUNG: Zusammenhang zwischen Befallsintensität und Temperatur während der einzelnen Stadien KATASTER-DETAIL: Delta T (Sommer, Herbst) +, dann Anzahl +; Delta T (Januar)+, dann Zeit der Puppenruhe - und weitere Überwinterung als Imago; T 〉 12°C, dann Schlüpfen; Delta T (Januar) + und Delta T (Februar)-, dann Anzahl -; Delta T (Winter) --, dann Anzahl --; Delta T (Winter) + und Delta T (Sommer) +, dann Anzahl ++;
    Keywords: Mitteleuropa ; 1. Hälfte 20. Jahrhundert ; Insekten ; Pfirsich ; Apfel ; Boden ; Ertrag ; Pflanzenschädling ; Temperatur ; Frost ; Obst
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  • 30
    facet.materialart.
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst, p. 29-33
    Publication Date: 1955
    Description: Untersuchungen zum Verlauf des Apfelwicklerfluges unter den in Mitteldeutschland vorherrschenden Witterungsbedingungen mit der Lichtfallenmethode KATASTER-BESCHREIBUNG: Zusammenhang zwischen Flugverhalten und Niederschlag, Temperatur und Wind KATASTER-DETAIL: Delta T - , dann Flug - Delta Nied + , dann Flug - T〈15°C (warme Tage), dann kein Flug; T〈14°C (kühle Tage), dann noch Flug; T〉= 20°C, dann Flug + (höchste Ergebnisse); Delta Wind -, dann Flug +; Wind〉 7 Windstärken, dann kein Flug
    Keywords: Naumburg ; 1954 ; Apfel ; Niederschlag ; Pflanzenschädling ; Temperatur ; Wind
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  • 31
    Publication Date: 1951
    Description: Beobachtungen zum Massenauftreten des Rübenderbrüßlers in Abhängigkeit von der vorherrschenden Witterung KATASTER-BESCHREIBUNG: Zusammenhang zwischen der Witterung (Bodentemperatur und Bodenfeuchte) und dem Massenauftreten des Käfers KATASTER-DETAIL: Delta Nied (Sommer) +, dann Mortalität +; Delta T (Sommer des Vorjahres) + und Delta Nied (Sommer des Vorjahres) - sowie Delta T ( Frühjahr des Schadjahres) +, dann Massenauftreten des Käfers +; Delta T: Tmit (Boden) 〉 10°C, Auskriechen der Käfer aus dem Boden
    Keywords: Mitteldeutschland ; 1947-1949 ; Insekten ; Zuckerrüben ; Boden ; Landwirtschaft ; Niederschlag ; Pflanzenschädling ; Temperatur ; Trockenheit ; Witterung
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  • 32
    facet.materialart.
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    In:  Nachr.bl. Deutsch. Pflanzenschutzdienst, p. 9-10
    Publication Date: 1958
    Description: Verbale Beobachtungen über das Freilandvorkommen der Zwiebellaus KATASTER-BESCHREIBUNG: Zusammenhang zwischen der Witterung (Temperatur) im Winter und dem Freilandauftreten der Laus KATASTER-DETAIL: Delta T (Winter) +, dann Massenvermehrung +
    Keywords: Hannover, Niedersachsen ; 1956-1957 ; Pflanzenschädling ; Temperatur ; Witterung
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  • 33
    facet.materialart.
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    In:  Beiträge zur Entomologie, Band 2, Nr. 2/3, p. 256-315
    Publication Date: 1952
    Description: Beobachtungen und Untersuchungen zur Biologie, Epidemiologie und Bekämpfung des Rübenderbrüßlers KATASTER-BESCHREIBUNG: Einflüsse der Witterung auf die Entwicklung und das Massenauftreten des Käfers KATASTER-DETAIL: Delta T und Delta Nied und Delta Sonn: T(Boden)〉8°C und Delta Nied -, Delta T (Luft) + und Delta Sonn +, dann Verlassen des Bodens; Delta T -, dann Unterbrechungen der Abwanderung +; Delta T und Delta Sonn: T〉=22°C und Sonnenschein, dann Flug; Delta T: T〉= 15-17°C, dann Reifung; T=26,2°C und Relf=30-37%, dann maximale Eizahl; T〈2°C, dann Erstarrungszustand; Delta Nied (Mai, Juni) -, dann Massenauftreten +; Delta T +, dann Eizahl +;
    Keywords: Sachsen-Anhalt ; 1950 ; Zuckerrüben ; Boden ; Niederschlag ; Pflanzenschädling ; Temperatur ; Witterung ; Sonnenscheindauer
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  • 34
    facet.materialart.
    Unknown
    In:  Mitteilungen aus der Biologischen Zentralanstalt für Land- und Forstwirtschaft Berlin-Dahlem, Heft 79
    Publication Date: 1954
    Description: Zusammenfassender Bericht über die in den Jahren 1947-1952 in Westdeutschland durchgeführten Untersuchungen zur Epidemiologie, Verbreitung, wirtschaftlichen Bedeutung und Bekämpfung dieser Virose KATASTER-BESCHREIBUNG: Hauptbefallsgebiete sind solche, mit mildem Winterklima, in denen die langjährigen Mittelwerte des kältesten Monats Januar nicht unter 0°C abfallen; KATASTER-DETAIL: Delta T(Sommer)+ und Delta Nied (Sommer) -, dann Delta t(Individualentwicklung der Überträger)- und Massenentwicklung (der Überträger) +; Delta T(Sommer)+ und Delta Nied (Sommer)-, dann Vergilbungsschäden +; Delta T - und Delta Lichtintensität -, dann Wirkung des Virus -;
    Keywords: Westdeutschland ; 1947-1952 ; Infektionskrankheiten ; Ertrag ; Niederschlag ; Pflanzenkrankheit ; Pflanzenschädling ; Temperatur ; Trockenheit ; Wachstum ; Witterung ; Düngung
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  • 35
    facet.materialart.
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    In:  Mitt. Biol. Bundesanst. Land-Fortwirtsch. Berlin-Dahlem, p.178-180
    Publication Date: 1959
    Description: Freilandversuche zur Bestimmung des 1. Schlüpftermins der Kohldrehherzmücke KATASTER-BESCHREIBUNG: Zusammenhang zwischen Temperatur und Beginn der Flugzeit KATASTER-DETAIL: Delta Nied -, dann Entwicklung -; Nied = 20mm (innerhalb weniger Tage) und T(Boden 5-10cm Tiefe)= 20-22°C, dann Ende Diapause und Entwicklung +; 1. Schlüpftermin=Beginn der Flugzeit: Bluncksche Wärmesummenregel: C-Wert = 160 , Schwellenwert = 7,2°C
    Keywords: DDR ; 1950-58 ; Insekten ; Boden ; Niederschlag ; Pflanzenschädling ; Temperatur
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  • 36
    facet.materialart.
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    In:  Nachrichtenblatt des Deutschen Pflanzenschutzdienstes, p. 171-172
    Publication Date: 1950
    Description: Bericht über die Beobachtungen zur Entwicklung und zum Auftreten der Möhrenfliege unter dem Einfluss der Witterung und der Lage KATASTER-BESCHREIBUNG: Einfluss der Witterung und der Lage auf die Befallsstärke der Fliege KATASTER-DETAIL: Delta Lichtintensität +, dann Möhrenfliegenbefall -; Delta Nied +, dann Entwicklung der Maden +; Delta Wind +, dann Befall -
    Keywords: Schleswig-Holstein ; 1948-1949 ; Insekten ; Niederschlag ; Pflanzenschädling ; Temperatur ; Trockenheit ; Wind ; Witterung ; Sonnenscheindauer ; Gemüse
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  • 37
    Publication Date: 1955
    Description: Untersuchungen zur Ermittlung der biotischen und abiotischen Faktoren, die Massenvermehrung fördern oder hemmen sowie die Überprüfung der gewonnenen Erkenntnisse durch eigene Beobachtungen KATASTER-BESCHREIBUNG: Abhängigkeit von der Wiiterung (Temperatur, Niederschlag, Luftfeuchte, Wind) im Hinblick auf das Massenauftreten KATASTER-DETAIL: T = 18°C, dann Beginn des Zufluges; 21°C 〈 T 〈 25°C, dann Optimum für Zuflug; Delta Relf -: Relf 〈 35%, dann Aktivität (Flugtätigkeit) -; Delta Nied +, dann Massenauftreten -; Delta Wind +, dann Flugtätigkeit -
    Keywords: Sachsen-Anhalt ; 1952-1953 ; Insekten ; Luftfeuchte ; Niederschlag ; Pflanzenschädling ; Temperatur ; Witterung ; Sonnenscheindauer ; Gemüse
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  • 38
    Publication Date: 1953
    Description: Beobachtungen zu den wichtigsten Massenwechselphasen, welche phänologisch mit Hilfe der Temperatursummenregel ausgewertet wurden sowie Beobachtungen zum Einfluss des Mikroklimas auf die Flugphase KATASTER-BESCHREIBUNG: Zusammenhang zwischen den wichtigsten Massenwechselperioden und der Temperatur, angegeben mit der mittleren Temperatursumme ab dem Eintritt des Vorfrühlings (Schneeglöckchenblüte); Einfluss von flugbegrenzenden Faktoren (Licht, Wind, Niederschlag) und flugbeeinflussenden Faktoren (Temperatur, Luftfeuchtigkeit) KATASTER-DETAIL: Temperatursumme = 160°C, dann Schlüpfen der ersten Fundatrixlarven; Temperatursumme = 360°C, dann Eintreten erster reifer Fundatrizen; Temperatursumme = 600°C, dann Reife der ersten fundatrigenen Fliegen und Anfang des fundatrigenen Zufluges; Temperatursumme = 1000-1050°C, dann Ende des fundatrigenen Zufluges und Anfang des virginogenen Zufluges; temperatursumme = 2280-2420°C, dann Ende des virginogenen Zufluges; Delta Lichtintensität + und Windgeschwindigkeit 〈 0,6m/s und T(Blattoberfläche ) 〉= 17°C, bzw. T (Luft) 〉= 15-16°C und Delta Nied -, dann Abflug +; Delta T +, dann Ablfug +, T 〉 20-26°C, dann Abflug -; Relf = 60%, dann optimaler Bereich für Abflug;
    Keywords: Quedlinburg, Thüringen ; 1949-1952 ; Luftfeuchte ; Klima ; Korrelationsmethode ; Niederschlag ; Pflanzenschädling ; Phänologie ; Temperatur ; Wind ; Witterung
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  • 39
    facet.materialart.
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst, p. 143-148
    Publication Date: 1953
    Description: Bericht über die Untersuchungen zur Frage der Abhängigkeit der Imagines von klimatischen Faktoren KATASTER-BESCHREIBUNG: Einfluss der Witterung (Temperatur, Wind, Sonnenscheindauer, Luftfeuchte) auf die Flugaktivität KATASTER-DETAIL: Delta T +: T= 18°C, dann Höchstwert an geschlüpften und geschlechtsreifen Käfern; T 〉 18°C oder T 〈 18°C, dann Zahl an geschlüpften und geschlechtsreifen Käfern -; Delta Sonn +, dann Flugaktivität +; T = 23°C und Relf = 70%, dann Optimum der Flugaktivität; T = 13°C, dann Flugaktivität verhindert Delta Wind +: Wind 〉 1m/s, dann Flugaktivität vermindert, Wind 〉 2m/s, dann Flugaktivität stark gehemmt
    Keywords: Sachsen-Anhalt ; 1951-1952 ; Insekten ; Luftfeuchte ; Korrelationsmethode ; Niederschlag ; Pflanzenschädling ; Temperatur ; Wind ; Witterung ; Sonnenscheindauer
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  • 40
    facet.materialart.
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    In:  Zeitschrift
    Publication Date: 1950
    Description: Detailierte Berichte über das Auftreten von Schaderregern in der Landwirtschaft für jedes Jahr; Zusammenhänge zu Witterungsbedingungen werden zu Beginn der entsprechenden Hefte, sowie teilw. bei Besprechung der jeweiligen Schaderreger hergestellt KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Westdeutschland, regional aufgelöst ; 1950-2008 ; Pflanzenkrankheit ; Pflanzenschädling
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  • 41
    Publication Date: 1951
    Description: Hopfenzünsler wurden im Januar aus Winterverstecken genommen und in Glaszylindern untergebracht, worin ihre Lebensdauer unter unterschiedlichen Temperaturen und rel. Luftfeuchten gemessen wurde. Bei niedrigen und hohen Temperaturen stellte sich die Luftfeuchte als entscheidender Faktor heraus, bei mittleren Temperaturen (10-15,5°C und 16-21,5°C) spielte auch die Temperatur eine Rolle. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Labor ; 1949-1950 ; Getreide ; Pflanzenschädling ; Hopfen
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  • 42
    facet.materialart.
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst 12, Heft 2; p.21-35
    Publication Date: 1958
    Description: Es wird eine Übersicht auf die Maikäferflüge der Jahre 1950-1957 in der DDR auf Bezirks- und Kreisebene gegeben. Diese Ergebnisse werden versucht zusammen mit älteren Daten über den Maikäferflug seit 1920 (teilweise wird Literatur erwähnt, die den Maikäferflug an einigen Standorten seit ca.1830 enthält) mit Temperaturwerten in Verbindung zu setzen, um die Periodizität des Maikäferfluges zu erklären. KATASTER-BESCHREIBUNG: Regel zum Einfluß der Temperatur auf die Entwicklungslänge von Melolontha melolontha L.. KATASTER-DETAIL: In Gebieten mit 4jährigem Entwicklungszyklus kann dieser verkürzt werden, wenn das langjährige mittlere Jahresmaximum der Temperatur von 12,6°C überschritten wird.
    Keywords: DDR ; 1950-1957 ; Forst ; Pflanzenschädling
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  • 43
    facet.materialart.
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst 12, Heft 7; p.121-133
    Publication Date: 1958
    Description: Der Autor beschreibt die Biologie, Entwicklung und Bekämpfung der Leinerdflöhe, sowie die Abhängigkeit bestimmter Lebensabläufe von klimatischen Parametern. KATASTER-BESCHREIBUNG: Schwellwerte (Temperatur und rel.Luftfeuchte) für das Verlassen der Winterquartiere und den Abflug vom Winterlager werden gegeben. KATASTER-DETAIL: Verlassen der Winterquartiere ab 11°C Bodentemperatur (14 Uhr, 2cm Tiefe) und maximal 20-22% Bodenfeuchtigkeit. Ab maximalen Lufttemp. 〉15°C setzt der Abflug vom Winterlager ein. Ausbildung ablegereifer Eier bei 18-20°C und 80-85% rel.F. -〉 14-16 Tage; bei 22-24°C -〉 8-10 Tage.
    Keywords: Aschersleben, Sachsen, Sachsen-Anhalt, Thüringen, Labor ; 1955-1957 ; Pflanzenschädling ; Lein
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  • 44
    facet.materialart.
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    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst 12, Heft 9; p.161-172
    Publication Date: 1958
    Description: Der Autor untersucht den Einfluß von Temperatur, Niederschlag, Sonnenscheindauer, Wind, Relief, Boden, Sorte, Bestandesalter und Parasiten auf das Auftreten der Luzerneblütengallmücke an verschiedenen Standorten in der DDR. KATASTER-BESCHREIBUNG: Eine Temperatur- und eine Feuchteregel zur Bestimmung des Massenauftretens des Schädlings werden entworfen. KATASTER-DETAIL: Mit einem Massenauftreten ist zu rechnen, wenn: 1. die Nds.summe(März-Mai bzw. Apr.-Juni)〉150mm oder die Nds.summe(März-Juni)〉200mm und gleichzeitig die Nds.summe(vor 3.und 4.Flugperiode)=30-50mm; 2. tmit(17Uhr, 2cm Tiefe & am Boden)〉=16°C, tmax(17Uhr, im Bestand)〉=20°C und tmin(17Uhr, im Bestand)〉=8°C für 10-20 Tage gilt.
    Keywords: DDR ; 1954-1956 ; Landwirtschaft ; Pflanzenschädling ; Luzerne
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  • 45
    Publication Date: 1950
    Description: Beobachtungen zum Auftreten von Roggengallmücke, Halmfliege, Getreidehalmwespe, Hafermilbe und Zwergzikade unter bestimmten Witterungsbedingungen (warme und trockene Sommer und Herbste) KATASTER-BESCHREIBUNG: Einfluss der Witterung (Temperatur und Niederschlag) im Sommer und Herbst auf das Auftreten der Getreideschädlinge KATASTER-DETAIL: Delta T (Sommer und Herbst) + und Delta Nied (Sommer und Hebrst) -, dann Auftreten +; Trockenperioden über mindestens 2 Jahre, dann Massenauftreten
    Keywords: Bayern ; 1947-1950 ; Anbautermine ; Landwirtschaft ; Niederschlag ; Pflanzenschädling ; Roggen ; Temperatur ; Trockenheit ; Weizen ; Witterung
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  • 46
    facet.materialart.
    Unknown
    In:  Nachrichtenblatt für den deutschen Pflanzenschutzdienst, Jahrgang 10 der neuen Folge, Heft 5, p. 97-105
    Publication Date: 1956
    Description: Untersuchungen zu ökologischen Grundlagen des Rapsstengelrüßlers zur Ermittlung des optimalen Bekämpfungstermins KATASTER-BESCHREIBUNG: Abhängigkeit der Aktivität der Käfer von der Temperatur KATASTER-DETAIL: Delta T+: Tmax (Boden, 2cm) 〉= 2°C, dann Verlassen des Winterlagers +; Tmax (Boden, 2cm) 〉 9°C, dann Verlassen des Winterlagers ++; Tmax (Luft) 〉= 9°C, dann Zuflug zu den Rapsfeldern +; Tmax (Luft) 〉 12°C, dann Massenzuflug
    Keywords: Sachsen-Anhalt ; 1953-1954 ; Insekten ; Boden ; Pflanzenschädling ; Temperatur ; Witterung ; Raps
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  • 47
    Publication Date: 2015-04-01
    Description: Afterburners for turbojet engines have, within the past decade, found increasing application in service aircraft. Practically all engines manufactured today are equipped with some form of afterburner, and its use has increased from what was originally a short-period thrust-augmentation application to an essential feature of the turbojet propulsion system for flight at supersonic speeds. The design of these afterburners has been based on extensive research and development effort in expanded laboratory facilities by both the NACA and the American engine industry. Most of the work of the engine industry, however, has either not been published or is not generally available owing to its proprietary nature. Consequently, the main bulk of research information available for summary and discussion is of NACA origin. However, because industrial afterburner development has closely followed NACA research, the omission is more one of technical detail than method or concept. One principal difficulty encountered in summarizing the work in this field is that sufficient knowledge does not yet exist to rationally or directly integrate the available background of basic combustion principles into combustor design. A further difficulty is that most of the experimental investigations that have been conducted were directed chiefly toward the development of specific afterburners for various engines rather than to the accumulation of systematic data. This work has, nonetheless, provided not only substantial improvements in the performance of afterburners but also a large fund of experimental data and an extensive background of experience in the field. Consequently, it is the purpose of the present chapter to summarize the many, and frequently unrelated, experimental investigations that have been conducted rather than to formulate a set of design rules. In the treatment of this material an effort has been made, however, to convey to the reader the "know how" acquired by research engineers in the course of afterburner studies.
    Keywords: Aircraft Propulsion and Power
    Type: Adaptation of Combustion Principles to Aircraft Propulsion. Volume II - Combustion in Air-Breathing Jet Engines
    Format: application/pdf
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  • 48
    Publication Date: 2015-04-01
    Description: In the early development of jet engines, it was occasionally found that excessive amounts of coke or other carbonaceous deposits were formed in the combustion chamber. Sometimes a considerable amount of smoke was noted in the-exhaust gases. Excessive coke deposits may adversely affect jet-engine performance in several ways. The formation of excessive amounts of coke on or just downstream of a fuel nozzle (figs. 116(a) and (b)) changes the fuel-spray pattern and possibly affects combustor life and performance. Similar effects on performance can result from the deposition of coke on primary-air entry ports (fig. 116(c)). Sea-level or altitude starting may be impaired by the deposition of coke on spark-plug electrodes (fig. 116(b)), deposits either grounding the electrodes completely or causing the spark to occur at positions other than the intended gap. For some time it was thought that large deposits of coke in turbojet combustion chambers (fig. 116(a)) might break away and damage turbine blades; however, experience has indicated that for metal blades this problem is insignificant. (Cermet turbine blades may be damaged by loose coke deposits.) Finally, the deposition of coke may cause high-temperature areas, which promote liner warping and cracking (fig. 116(d)) from excessive temperature gradients and variations in thermal-expansion rates. Smoke in the exhaust gases does not generally impair engine performance but may be undesirable from a tactical or a nuisance standpoint. Appendix B of reference 1 and references 2 to 4 present data obtained from full-scale engines operated on test stands and from flight tests that indicate some effects on performance caused by coke deposits and smoke. Some information about the mechanism of coke formation is given in reference 5 and chapter IX. The data indicate that (1) high-boiling fuel residuals and partly polymerized products may be mixed with a large amount of smoke formed in the gas phase to account for the consistency, structure, and chemical composition of the soft coke in the dome and (2) the hard deposits on the liner are similar to petroleum coke and may result from the liquid-phase thermal cracking of the fuel. During the early development period of jet engines, it was noted that the excessive coke deposits and exhaust smoke were generally obtained when fuel-oil-type fuels were used. Engines using gasoline-type fuels were relatively free from the deposits and smoke. These results indicated that some type of quality control would be needed in fuel specifications. Also noted was the effect of engine operating conditions on coke deposition. It is possible that, even with a clean-burning fuel, an excessive amount of coke could be formed at some operating conditions. In this case, combustor redesign could possibly reduce the coke to a tolerable level. This chapter is a summary of the various coke-deposition and exhaust-smoke problems connected- with the turbojet combustor. Included are (1) the effect of coke deposition on combustor life or durability and performance; (2) the effect of combustor design, operating conditions, inlet variables, and fuel characteristics on coke deposition; (3) elimination of coke deposits; (4) the effect of operating conditions and fuel characteristics on formation of exhaust smoke; and (5) various bench test methods proposed for determining and controlling fuel quality.
    Keywords: Aircraft Propulsion and Power
    Type: Adaptation of Combustion Principles to Aircraft Propulsion. Volume II - Combustion in Air-Breathing Jet Engines
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  • 49
    Publication Date: 2015-04-01
    Description: Combustion must be maintained in the turbojet-engine combustor over a wide range of operating conditions resulting from variations in required engine thrust, flight altitude, and flight speed. Furthermore, combustion must be efficient in order to provide the maximum aircraft range. Thus, two major performance criteria of the turbojet-engine combustor are (1) operatable range, or combustion limits, and (2) combustion efficiency. Several fundamental requirements for efficient, high-speed combustion are evident from the discussions presented in chapters III to V. The fuel-air ratio and pressure in the burning zone must lie within specific limits of flammability (fig. 111-16(b)) in order to have the mixture ignite and burn satisfactorily. Increases in mixture temperature will favor the flammability characteristics (ch. III). A second requirement in maintaining a stable flame -is that low local flow velocities exist in the combustion zone (ch. VI). Finally, even with these requirements satisfied, a flame needs a certain minimum space in which to release a desired amount of heat, the necessary space increasing with a decrease in pressure (ref. 1). It is apparent, then, that combustor design and operation must provide for (1) proper control of vapor fuel-air ratios in the combustion zone at or near stoichiometric, (2) mixture pressures above the minimum flammability pressures, (3) low flow velocities in the combustion zone, and (4) adequate space for the flame.
    Keywords: Aircraft Propulsion and Power
    Type: Adaptation of Combustion Principles to Aircraft Propulsion. Volume II - Combustion in Air-Breathing Jet Engines
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  • 50
    Publication Date: 2015-04-01
    Description: From considerations of safety and reliability in performance of gas-turbine aircraft, it is clear that engine starting and acceleration are of utmost importance. For this reason extensive efforts have been devoted to the investigation of the factors involved in the starting and acceleration of engines. In chapter III it is shown that certain basic combustion requirements must be met before ignition can occur; consequently, the design and operation of an engine must be tailored to provide these basic requirements in the combustion zone of the engine, particularly in the vicinity of the ignition source. It is pointed out in chapter III that ignition by electrical discharges is aided by high pressure, high temperature, low gas velocity and turbulence, gaseous fuel-air mixture, proper mixture strength, and-an optimum spark. duration. The simultaneous achievement of all these requirements in an actual turbojet-engine combustor is obviously impossible, yet any attempt to satisfy as many requirements as possible will result in lower ignition energies, lower-weight ignition systems, and greater reliability. These factors together with size and cost considerations determine the acceptability of the final ignition system. It is further shown in chapter III that the problem of wall quenching affects engine starting. For example, the dimensions of the volume to be burned must be larger than the quenching distance at the lowest pressure and the most adverse fuel-air ratio encountered. This fact affects the design of cross-fire tubes between adjacent combustion chambers in a tubular-combustor turbojet engine. Only two chambers in these engines contain spark plugs; therefore, the flame must propagate through small connecting tubes between the chambers. The quenching studies indicate that if the cross-fire tubes are too narrow the flame will not propagate from one chamber to another. In order to better understand the role of the basic factors in actual engine operation, many investigations have been conducted in single combustors from gas-turbine engines and in full-scale engines in altitude tanks and in flight. The purpose of the present chapter is to discuss the results of such studies and, where possible, to interpret these results qualitatively in terms of the basic requirements reported in chapter III. The discussion parallels the three phases of turbojet engine starting: (1) Ignition of the fuel-air mixture (2) Propagation of flame throughout the combustion zone (3) Acceleration of the engine to operating speed.
    Keywords: Aircraft Propulsion and Power
    Type: Adaptation of Combustion Principles to Aircraft Propulsion. Volume II - Combustion in Air-Breathing Jet Engines
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  • 51
    Publication Date: 2015-04-01
    Description: Studies of the fundamental processes of combustion are usually concerned with wide ranges of investigation of individual processes. In general, each fundamental combustion process may be studied in an environment that is most suited to its evaluation and possibly unrelated basically to any practical application. The majority of the data presented in volume I of this series concern the fundamental aspects of combustion as functions of the individual occurrence of various contributing processes. In a jet engine, however, the various fundamental combustion processes may occur simultaneously and may interact. Furthermore, the engine environment usually does not permit independent variation of single combustion parameters, since specified operating conditions impose specific values on the parameters. In volume II, data are presented to show the effect of operating conditions on the over-all combustion process in different combustion components. To show the effect of operating conditions, it is necessary to specify the range of these conditions within which combustion components may operate. Therefore, this chapter presents only the operating conditions that might be required in the primary combustors and afterburners of typical current turbojet engines. (Corresponding information on ram-jet engines is presented in ch. xisi.) This chapter is not intended to serve as an explanation of engine operation. The operating conditions of the combustion components are presented in terms of total pressures and temperatures at the primary-combustor and afterburner inlets, reference velocities and outlet total temperatures of the primary combustors, and velocities at the plane of the flameholder in the afterburners. The data are presented to relate the operating regions of typical current turbojet combustion components to flight altitudes, Mach numbers, and modes of engine operation. Specifically, data are presented for the combustion parameters of the primary combustor and afterburner of three turbojet engines having rated compressor total-pressure ratios of 5, 8, and 12 under full-throttle conditions. Operational data for the primary combustor also include part-throttle operation at 70, 80, and 90 percent of rated engine speed and windmifling operation. The range of flight conditions includes altitudes from sea level to 65,000 feet and flight Mach numbers from zero to 1.6.
    Keywords: Aircraft Propulsion and Power
    Type: Adaptation of Combustion Principles to Aircraft Propulsion. Volume II - Combustion in Air-Breathing Jet Engines
    Format: text
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  • 52
    Publication Date: 2019-05-11
    Description: Three highly polished 15- included- angle cone- cylinders with hemispherical tips of several diameters ( 2, 3, and 4 in.) have been flown in order to obtain boundary- layer transition data at very low wall to local stream temperature ratios, and heat- transfer data. All surfaces had a 2-microinch average roughness height. Laminar flow existed over the entire hemispherical nose of the 2- and 3-inch-tip- diameter models throughout the complete flight history. Extreme cooling to wall to local stream temperature ratios at the sonic point as low as 0.20 did not cause transition on the nose for diameters as large as 3 inches. However, extreme cooling did cause early transition on the 4-inch model where it appears probable that transition occurred forward of the 45 station at a wall to local stream temperature ratio of about 0.26. Variations in tip diameter influenced transition downstream of the nose under conditions of extreme cooling. The 2-inch- tip model was laminar at all cone- cylinder stations at temperature ratios as low as 0.32 whereas the 3- and 4-inch-tip models were turbulent at the same local flow conditions but at higher wall to local temperature ratios. Transition on the cone and cylinder of the 3- and 4-inch- tip bodies appeared to be sensitive to local Mach number, and occurred at higher local temperature ratios when values of local Mach number were higher. Increasing the nose diameter from 2 to 3 inches significantly changed the local flow conditions for which laminar flow existed on the cone- cylinder afterbody. However, a further increase in tip size t o a 4-inch diameter had no discernable effect on the local flow conditions at transition. The transition results of the 3- and 4-inch-nose-diameter smooth bodies are similar to those observed on a 7/8-inch-nose-diameter body with roughened surfaces. Turbulent boundary layers resulted in both cases at very low wall to local stream temperature ratios. Both laminar and turbulent heat-transfer data were in good agreement with theoretical Stanton numbers when heat-transfer reduction due to tip blunting was considered.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-3-4-59E , GRC-E-DAA-TN65086
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  • 53
    Publication Date: 2019-06-28
    Description: A comparison of the operating characteristics of 75-millimeter-bore (size 215) cylindrical-roller one-piece inner-race-riding cage-type bearings was made using a laboratory test rig and a turbojet engine. Cooling correlation parameters were determined by means of dimensional analysis, and the generalized results for both the inner- and outer-race bearing operating temperatures are compared for the laboratory test rig and the turbojet engine. Inner- and outer-race cooling-correlation curves were obtained for the turbojet-engine turbine-roller bearing with the same inner- and outer-race correlation parameters and exponents as those determined for the laboratory test-rig bearing. The inner- and outer-race turbine roller-bearing temperatures may be predicted from a single curve, regardless of variations in speed, load, oil flow, oil inlet temperature, oil inlet viscosity, oil-jet diameter or any combination of these parameters. The turbojet-engine turbine-roller-bearing inner-race temperatures were 30 to 60 F greater than the outer-race-maximum temperatures, the exact values depending on the operating condition and oil viscosity; these results are in contrast to the laboratory test-rig results where the inner-race temperatures were less than the outer-race-maximum temperatures. The turbojet-engine turbine-roller bearing, maximum outer-race circumferential temperature variation was approximately 30 F for each of the oils used. The effect of oil viscosity on inner- and outer-race turbojet-engine turbine-roller-bearing temperatures was found to be significant. With the lower viscosity oil (6x10(exp -7) reyns (4.9 centistokes) at 100 F; viscosity index, 83), the inner-race temperature was approximately 30 to 35 F less than with the higher viscosity oil (53x10(exp -7) reyns (42.8 centistokes) at 100 F; viscosity index, 150); whereas the outer-race-maximum temperatures were 12 to 28 F lower with the lower viscosity oil over the DN range investigated.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E51I05
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  • 54
    Publication Date: 2019-06-28
    Description: Average spanwise blade temperatures and cooling-air pressure losses through a small (1.4-in, span, 0.7-in, chord) air-cooled turbine blade were calculated and are compared with experimental nonrotating cascade data. Two methods of calculating the blade spanwise metal temperature distributions are presented. The method which considered the effect of the length-to-diameter ratio of the coolant passage on the blade-to-coolant heat-transfer coefficient and assumed constant coolant properties based on the coolant bulk temperature gave the best agreement with experimental data. The agreement obtained was within 3 percent at the midspan and tip regions of the blade. At the root region of the blade, the agreement was within 3 percent for coolant flows within the turbulent flow regime and within 10 percent for coolant flows in the laminar regime. The calculated and measured cooling-air pressure losses through the blade agreed within 5 percent. Calculated spanwise blade temperatures for assumed turboprop engine operating conditions of 2000 F turbine-inlet gas temperature and flight conditions of 300 knots at a 30,000-foot altitude agreed well with those obtained by the extrapolation of correlated experimental data of a static cascade investigation of these blades.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E58E20
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  • 55
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-06-28
    Description: Some of the considerations involved in the design of aircraft fuel tanks for liquid hydrogen are discussed herein. Several of the physical properties of metals and thermal insulators in the temperature range from ambient to liquid-hydrogen temperatures are assembled. Calculations based on these properties indicate that it is possible to build a large-size liquid-hydrogen fuel tank which (1) will weigh less then 15 percent of the fuel weight, (2) will have a hydrogen vaporization rate less than 30 percent of the cruise fuel-flow rate, and (3) can be held in a stand-by condition and readied for flight in a short time.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E55F22
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  • 56
    Publication Date: 2019-06-28
    Description: The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E54I07
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  • 57
    Publication Date: 2019-06-28
    Description: A literature survey was conducted to determine the relation between aircraft ignition sources and inflammables. Available literature applicable to the problem of aircraft fire hazards is analyzed and, discussed herein. Data pertaining to the effect of many variables on ignition temperatures, minimum ignition pressures, and minimum spark-ignition energies of inflammables, quenching distances of electrode configurations, and size of openings incapable of flame propagation are presented and discussed. The ignition temperatures and the limits of inflammability of gasoline in air in different test environments, and the minimum ignition pressure and the minimum size of openings for flame propagation of gasoline - air mixtures are included. Inerting of gasoline - air mixtures is discussed.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-TN-2227
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  • 58
    Publication Date: 2019-06-28
    Description: Tests of two propellers having two blades and differing only in the inboard pitch distribution were made in the Langley 8-foot highspeed tunnel to determine the effect of inboard pitch distribution on propeller performance. propeller was designed for operation in the reduced velocity region ahead of an NACA cowling; the inboard pitch distribution of the modified propeller was increased for operation at or near free-stream velocities, such as would be obtained in a pusher installation. conditions covering climb, cruise, and high-speed operation. Wake surveys were taken behind the propellers in order to determine the distribution of thrust along the blades and to aid in the analysis of the results. Test results showed that the modified propeller was about 2.5 percent less efficient for a typical climb condition at all altitudes, 2 percent more efficient for one cruise condition, and 5 percent more efficient for high-speed operation. speed condition, the modified propeller showed a 6-percent loss in efficiency due to compressibility; whereas the original propeller showed an 11-percent efficiency loss due to compressiblity. The lower compressibility loss for the modified propeller resulted from the fact that the inboard sections of this propeller could operate at increased thrust loading after compressibility losses had occurred at the outboard sections.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-TN-2268
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  • 59
    Publication Date: 2019-05-23
    Description: Pressure distribution prediction methods for low flow radial impellers
    Keywords: Aircraft Propulsion and Power
    Type: NASA-CR-62246 , PWA-FR-1276
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  • 60
    Publication Date: 2019-06-28
    Description: As part of a general investigation of propellers at high forward speeds, tests of two 2-blade propellers having the NACA 4-(3)(8)-03 and NACA 4-(3)(8)-45 blade designs have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.725 to establish in detail the changes in propeller characteristics due to compressibility effects. These propellers differed primarily only in blade solidity, one propeller having 50 percent and more solidity than the other. Serious losses in propeller efficiency were found as the propeller tip Mach number exceeded 0.91, irrespective of forward speed or blade angle. The magnitude of the efficiency losses varied from 9 percent to 22 percent per 0.1 increase in tip Mach number above the critical value. The range of advance ratio for peak efficiency decreased markedly with increase of forward speed. The general form of the changes in thrust and power coefficients was found to be similar to the changes in airfoil lift coefficient with changes in Mach number. Efficiency losses due to compressibility effects decreased with increase of blade width. The results indicated that the high level of propeller efficiency obtained at low speeds could be maintained to forward sea-level speeds exceeding 500 miles per hour.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-TR-999
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  • 61
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-06-28
    Description: An investigation has been made to explore the possibilities of axial-flow compressors operating with supersonic velocities into the blade rows. Preliminary calculations showed that very high pressure ratios across a stage, together with somewhat increased mass flows, were apparently possible with compressors which decelerated air through the speed of sound in their blading. The first phase of the investigation was the development of efficient supersonic diffusers to decelerate air through the speed of sound. The present report is largely a general discussion of some of the essential aerodynamics of single-stage supersonic axial-flow compressors. As an approach to the study of supersonic compressors, three possible velocity diagrams are discussed briefly. Because of the encouraging results of this study, an experimental single-stage supersonic compressor has been constructed and tested in Freon-12. In this compressor, air decelerates through the speed of sound in the rotor blading and enters the stators at subsonic speeds. A pressure ratio of about 1.8 at an efficiency of about 80 percent has been obtained.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-TR-974 , NACA-ACR-L6D02 , NACA-AR-36
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  • 62
    Publication Date: 2019-06-27
    Description: Sound pressure levels, frequency spectrum, and jet velocity profiles are presented for an engine-afterburner combination at various values of afterburner fuel - air ratio. At the high fuel-air ratios, severe low-frequency resonance was encountered which represented more than half the total energy in the sound spectrum. At similar thrust conditions, lower sound pressure levels were obtained from a current fighter air craft with a different afterburner configuration. The lower sound pressure levels are attributed to resonance-free afterburner operation and thereby indicate the importance of acoustic considerations in afterburner design.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E54G07
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  • 63
    Publication Date: 2019-06-27
    Description: Two short turbojet combustors designed for use with vaporized hydrocarbon fuels were tested in a one-quarter annular duct. The experimental combustors consisted of many small "swirl-can" combustor elements manifolded together. This design approach allowed the secondary mixing zone to be considerably reduced over that of conventional combustors. The over-all combustion lengths, for the two configurations were 13.5 and 11.0 inches, approximately one-half the length of the shortest conventional combustors. These short combustors did not provide combustion efficiencies as high as those for conventional combustors at low pressures. However, over the range of combustor-inlet total-pressures expected in aircraft capable of flight at Mach numbers of 2.5 and above, these short combustors gave very high efficiencies. A combustion efficiency of 97 percent was obtained at a combustor-inlet total-pressure of 25.0 inches of mercury absolute, reference velocity of 120 feet per second, and inlet-air total temperature of 1160 deg R. By proportioning the fuel flow between the manifold rows of can combustor elements, control of the combustor-outlet radial total-temperature profile was demonstrated. Combustor totalpressure loss varied from 0.75 percent of the inlet total pressure at isothermal conditions and a reference velocity of 75 feet per second to 5.5 percent at a total-temperature ratio of 1.8 and a reference velocity of 180 feet per second.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E57J03
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  • 64
    Publication Date: 2019-06-27
    Description: This analysis investigates the application of gas turbine engines at a cruise Mach number of 4.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-TM-X-60935 , NACA-C-8548
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  • 65
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-07-20
    Description: This report presents the results of an evaluation of the communications system performance during the Apollo 7 mission. The report includes, in addition to a communications system performance evaluation presented previously (Reference 1 of Appendix A), a supplemental evaluation of additional data.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-TM-X-62557 , MSC-PA-R-68-15-SUPPL-3 , JSC-E-DAA-TN70654
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  • 66
    Publication Date: 2019-06-27
    Description: An experimental investigation was conducted to determine the cooling effectiveness of a wide variety of air-cooled turbine-blade configurations. The blades, which were tested in the turbine of a - commercial turbojet engine that was modified for this investigation by replacing two of the original blades with air-cooled blades located diametrically opposite each other, are untwisted, have no aerodynamic taper, and have essentially the same external profile. The cooling-passage configuration is different for each blade, however. The fabrication procedures were varied and often unique. The blades were fabricated using methods most suitable for obtaining a small number of blades for use in the cooling investigations and therefore not all the fabrication procedures would be directly applicable to production processes, although some of the ideas and steps might be useful. Blade shells were obtained by both casting and forming. The cast shells were either welded to the blade base or cast integrally with the base. The formed shells were attached to the base by a brazing and two welding methods. Additional surface area was supplied in the coolant passages by the addition of fins or tubes that were S-brazed. to the shell. A number of blades with special leading- and trailing-edge designs that provided added cooling to these areas were fabricated. The cooling effectiveness and purposes of the various blade configurations are discussed briefly.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E51E23 , REPT-2203
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  • 67
    Publication Date: 2019-08-16
    Description: Contents: Preliminary notes on the efficiency of propulsion systems; Part I: Propulsion systems with direct axial reaction rockets and rockets with thrust augmentation; Part II: Helicoidal reaction propulsion systems; Appendix I: Steady flow of viscous gases; Appendix II: On the theory of viscous fluids in nozzles; and Appendix III: On the thrusts augmenters, and particularly of gas augmenters
    Keywords: Aircraft Propulsion and Power
    Type: NACA-TM-1259
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  • 68
    Publication Date: 2019-07-11
    Description: A program was conducted in an altitude facility at the NACA Lewis laboratory to investigate the effects of rapid inlet pressure oscillations on the operation of a current turbo jet engine. These pressure oscillations were approximately sinusoidal in form and were generated to cover a frequency range of 2 to 75 cycles per second and an amplitude range of 10 to 70 percent of the free-stream total pressure. As the oscillation progressed through the compressor, the amplitude was attenuated considerably and a relatively large phase shift (lag) occurred. Engine stall limits obtained during pressure oscillations differed from quasi-steady-state stall limits as defined by over-all compressor pressure ratio.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E58A03
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  • 69
    Publication Date: 2019-07-11
    Description: Strain-gages were used to measure blade vibrations causing failures in the third stage of a production 11-stage axial-flow compressor. After the serious third-stage vibration was detected, a series of investigations were conducted with second-stage vane assemblies of varying angles of incidence. Curves presented herein show the effect of varying the angle of incidence of second-stage vane assembly on third-stage rotor-blade vibration amplitude and engine performance. A minimum vibration amplitude was obtained without greatly affecting the engine performance with a second-stage vane assembly of 9deg. greater angle of incidence than the assembly normally furnished with the engine.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE51F08
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  • 70
    Publication Date: 2019-07-11
    Description: An investigation was conducted to determine the effects of water injection on the over-all performance of a modified J33-A-27 turbojet-engine compressor at the design equivalent speed of 11,800 rpm. The water-air ratio by weight was 0.05. With water injection the peak pressure ratio increased 9.0 per- cent, the maximum efficiency decreased 15 percent (actual numerical difference 0.12), and. the maximum total weight flow increased 9.3 percent.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE50F14
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  • 71
    Publication Date: 2019-07-11
    Description: An investigation of the altitude performance characteristics of an Allison J35-A-17 turbojet engines have been conducted in an altitude chamber at the NACA Lewis laboratory. Engine performance was obtained over a range of altitudes from 20,000 to 60,000 feet at a flight Mach number of 0.62 and a range of flight Mach numbers from 0.42 to 1.22 at an altitude of 30,000 feet. The performance of the engine over the range investigated could be generalized up to an altitude of 30,000 feet. Performance of the engine at any flight Mach number in the range investigated can be predicted for those operating condition a t which critical flow exits in the exhaust nozzle with the exception of the variables corrected net thrust, and net-thrust specific fuel consumption.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E50I15
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  • 72
    Publication Date: 2019-07-11
    Description: The compressor from the XT-46 turbine-propeller engine was revised by removing the last two rows of stator blades and by eliminating the interstage leakage paths described in a previous report. With the revised compressor, the flow choking point shifted upstream into the last rotor-blade row but the maximum weight flow was not increased over that of the original compressor. The flow range of the revised compressor was reduced to about two-thirds that obtained with the original compressor. The later stages of the compressor did not produce the design static-pressure increase probably because of excessive boundary-layer build-up in this region. Measurements obtained in the ninth-stage stator showed that the performance up to this station was promising but that the last three stages of the compressor were limiting the useful operating range of the preceding stages. Some modifications in flow-passage geometry and blade settings are believed to be necessary, however, before any major improvements in over-all compressor performance can be obtained.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE50J10
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  • 73
    Publication Date: 2019-07-11
    Description: The multistage turbine from the J73 turbojet engine has previously been investigated with standard and with reduced-chord rotor blading in order to determine the individual performance characteristics of each configuration over a range of over-all pressure ratio and speed. Because both turbine configurations exhibited peak efficiencies of over 90 percent, and because both units had relatively wide efficient operating ranges, it was considered of interest to determine the performance of the first stage of the turbine as a separate component. Accordingly, the standard-bladed multistage turbine was modified by removing the second-stage rotor disk and stator and altering the flow passage so that the first stage of the unit could be operated independently. The modified single-stage turbine was then operated over a range of stage pressure ratio and speed. The single-stage turbine operated at a peak brake internal efficiency of over 90 percent at an over-all stage pressure ratio of 1.4 and at 90 percent of design equivalent speed. Furthermore, the unit operated at high efficiencies over a relatively wide operating range. When the single-stage results were compared with the multistage results at the design operating point, it was found that the first stage produced approximately half the total multistage-turbine work output.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E53L28A
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  • 74
    Publication Date: 2019-07-11
    Description: The steady-state over-all performance characteristics of the J65-B3 turbojet engine were determined in an altitude test chamber for four exhaust-nozzle areas at Reynolds number indices of 0.8, 0.4, and 0.2. This range of Reynolds number indices corresponds to a range of altitudes from about sea level to 51,500 feet at a flight Mach number of 0.8. Generalized data are presented to allow calculation of engine performance at any flight condition corresponding to a Reynolds number index within the range investigated. Engine performance calculated from these generalized data is presented for seven altitudes over a range of flight speeds from zero to about 1100 knots. The use of an exhaust nozzle sized to give rated perforce at sea level would permit operation near the point of minimum specific fuel consumption for a wide range of flight conditions and engine speeds.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE55C08
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  • 75
    Publication Date: 2019-07-11
    Description: The power plant from a Mark 25 aerial torpedo was investigated both as a two-stage turbine and as a single-stage modified turbine to determine the effect on overall performance of nozzle size and shape, first-stage rotor-blade configuration, and axial nozzle-rotor running clearance. Performance was evaluated in terms of brake, rotor, and blade efficiencies. All the performance data were obtained for inlet total to outlet static pressure ratios of 8, 15 (design), and 20 with inlet conditions maintained constant at 95 pounds per square inch gage and 1000 F for rotor speeds from approximately 6000 to 18,000 rpm.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE50D12
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  • 76
    Publication Date: 2019-07-11
    Description: An investigation of a decoupler and a controlled-feathering device incorporated with the YT-56A turboprop engine has been made to determine the effectiveness of these devices in reducing the high negative thrust (drag) which accompanies power failure of this type of engine. Power failures were simulated by fuel cut-off, both without either device free to operate, and with each device free to operate singly. The investigation was made through an airspeed range from 50 to 230 mph. It was found that with neither device free to operate, the drag levels realized after power failures at airspeeds above 170 mph would impose vertical tail loads higher than those allowable for the YC-130, the airplane for which the test power package was designed. These levels were reached in approximately one second. The maximum drag realized after power failure was not appreciably altered by the use of the decoupler although the decoupler did put a limit on the duration of the peak drag. The controlled-feathering device maintained a level of essentially zero drag after power failure. The use of the decoupler in the YT-56A engine complicates windmilling air-starting procedures and makes it necessary to place operating restrictions on the engine to assure safe flight at low-power conditions,
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SA54I09
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  • 77
    Publication Date: 2019-07-11
    Description: Internal performance of an XJ79-GE-1 variable ejector was experimentally determined with the primary nozzle in a representative nonafterburning position. Jet-thrust and air-handling data were obtained in quiescent air for 11 selected ejector configurations over a wide range of operation. Additional data, at specific operating conditions, were obtained which indicate the ejector diameter ratio for peak jet-thrust performance. The experimental ejector data are presented in both graphical and tabulated form.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E56E23
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  • 78
    Publication Date: 2019-07-12
    Description: An investigation was conducted in an altitude test chamber at the NACA Lewis laboratory to determine the effect of a revision of the rated engine operating conditions and modifications to the afterburner fue1 system, flameholder, and shell cooling on the augmented performance of the J71-A-2 (x-29) turbo jet engine operating at altitude . The afterburner modifications were made by the manufacturer to improve the endurance at sea-level, high-pressure conditions and to reduce the afterburner shell temperatures. The engine operating conditions of rated rotational speed and turbine-outlet gas temperature were increased. Data were obtained at conditions simulating flight at a Mach number of 0.9 and at altitudes from 40,000 to 60,000 feet. The afterburner modifications caused a reduction in afterburner combustion efficiency. The increase in rated engine speed and turbine-outlet temperature coupled with the afterburner modifications resulted in the over-all thrust of the engine and afterburner being unchanged at a given afterburner equivalence ratio, while the specific fuel consumption was increased slightly. A moderate shift in the range of equivalence ratios over which the afterburner would operate was encountered, but the maximum operable altitude remained unaltered. The afterburner-shell temperatures were also slightly reduced because of the modifications to the afterburner.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE55D12
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  • 79
    Publication Date: 2019-07-12
    Description: Annular blade-element data obtained primarily from single-stage compressor installations are correlated over a range of inlet Mach numbers and cascade geometry. The correlation curves are presented in such a manner that they are related directly to the low-speed two-dimensional-cascade data of part VI of this series. Thus, the data serve as both an extension and a verification of the two-dimensional-cascade data. In addition, the correlation results are applied to compressor design.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E55G02
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  • 80
    Publication Date: 2019-07-12
    Description: An investigation of the endurance characteristics, at high Mach number, of the J65-W-7 engine was made in an altitude chamber at the Lewis laboratory. The investigation was made to determine whether this engine can be operated at flight conditions of Mach 2 at 35,000-feet altitude (inlet temperature, 250 F) as a limited-service-life engine Failure of the seventh-stage aluminum compressor blades occurred in both engines tested and was attributed to insufficient strength of the blade fastenings at the elevated temperatures. For the conditions of these tests, the results showed that it is reasonable to expect 10 to 15 minutes of satisfactory engine operation before failure. The high temperatures and pressures imposed upon the compressor housing caused no permanent deformation. In general, the performance of the engines tested was only slightly affected by the high ram conditions of this investigation. There was no discernible depreciation of performance with time prior to failure.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE55B07
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  • 81
    Publication Date: 2019-07-12
    Description: The operational characteristics of a J57-P1 turbojet engine have been investigated at altitudes between 15,000 and 66,000 feet in the Lewis altitude wind tunnel. Included in this study is a discussion of fuel nozzle coking, the altitude operating limits with and without the standard engine control, the compressor surge characteristics, and the engine starting and windmilling characteristics. Severe circumferential turbine outlet temperature gradients which occurred at high altitude as a result of fuel nozzle coking were alleviated by the manufacturer's change in the fuel flow divider schedule and in a nozzle gasket material. Compressor air bleed is required to prevent surge of the outboard compressor in the low engine speed region. The maximum altitude at which the engine was operated without the control was about 66,000 feet at 0.8 flight Mach number and at a reduced engine speed to avoid compressor surge; with the engine control in operation, the altitude operating limit is reduced to approximately 59,000 feet. The maximum altitude at which the engine was started was about 40,000 feet.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE54C31
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  • 82
    Publication Date: 2019-07-12
    Description: An investigation to increase the compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine at high equivalent speeds was conducted at the NACA Lewis altitude wind tunnel. This report evaluates the compressor modifications which were restricted to (1) twisting rotor blades (in place) to change blade section angles and (2) inserting new stator diaphragms with different blade angles. Such configuration changes could be incorporated quickly and easily in existing engines at overhaul depots. It was found that slight improvements in the compressor surge limit were possible by compressor blade adjustment. However, some of the modifications also reduced the engine air flow and hence penalized the thrust. The use of a mixer assembly at the compressor outlet improved the surge limit with no appreciable thrust penalty.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE52G03
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  • 83
    Publication Date: 2019-08-17
    Description: The effect of stator and rotor aspect ratio on transonic-turbine performance was experimentally investigated. The stator aspect ratios covered were 1.6. 0.8, and 0.4, while the rotor aspect ratios investigated were 1.46 and 0.73. It was found that the observed variation in turbine design-point efficiency was negligible. Thus, within the range of aspect ratio investigated, these results verify for turbines operating in the transonic flow range the finding of a reference report, which showed analytically that, if blade shape and solidity are held constant, the aspect ratio may be varied over a wide range without appreciable change in turbine efficiency.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-2-11-59E , E-177
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  • 84
    Publication Date: 2019-08-17
    Description: The suitability of cermets for turbine stator blades of a modified turbojet engine was determined at an average turbine-inlet-gas temperature of 2000 F. Such an increase in temperature would yield a premium in thrust from a service engine. Because the cermet blades require no cooling, all the available compressor bleed air could be used to cool a turbine made from conventional ductile alloys. Cermet blades were first run in 100-hour endurance tests at normal gas temperatures in order to evaluate two methods for mounting them. The elevated gas-temperature test was then run using the method of support considered best for high-temperature operation. After 52 hours at 2000 F, one of the group of four cermet blades fractured probably because of end loads resulting from thermal distortion of the spacer band of the nozzle diaphragm. Improved design of a service engine would preclude this cause of premature failure.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-2-13-59E , E-147
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  • 85
    Publication Date: 2019-08-17
    Description: An investigation was conducted in a modified turbojet engine to determine the cooling characteristics of the semistrut corrugated air- cooled turbine blade and to compare and evaluate a leading-edge tip cap as a means for improving the leading-edge cooling characteristics of cooled turbine blades. Temperature data were obtained from uncapped air-cooled blades (blade A), cooled blades with the leading-edge tip area capped (blade B), and blades with slanted corrugations in addition to leading-edge tip caps (blade C). All data are for rated engine speed and turbine-inlet temperature (1660 F). A comparison of temperature data from blades A and B showed a leading-edge temperature reduction of about 130 F that could be attributed to the use of tip caps. Even better leading-edge cooling was obtained with blade C. Blade C also operated with the smallest chordwise temperature gradients of the blades tested, but tip-capped blade B operated with the lowest average chordwise temperature. According to a correlation of the experimental data, all three blade types 0 could operate satisfactorily with a turbine-inlet temperature of 2000 F and a coolant flow of 3 percent of engine mass flow or less, with an average chordwise temperature limit of 1400 F. Within the range of coolant flows investigated, however, only blade C could maintain a leading-edge temperature of 1400 F for a turbine-inlet temperature of 2000 F.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-2-9-59E
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  • 86
    Publication Date: 2019-08-16
    Description: A lightweight turbine rotor assembly was devised, and components were evaluated in a full-scale jet engine. Thin sheet-metal airfoils were brazed to radial fingers that were an integral part of a number of thin disks composing the turbine rotor. Passages were provided between the disks and in the blades for air cooling. The computed weight of the assembly was 50 percent less than that of a similar turbine of normal construction used in a conventional turbojet engine. Two configurations of sheet-metal test blades simulating the manner of attachment were fabricated and tested in a turbojet engine at rated speed and temperature. After 8-1/2 hours of operation pieces broke loose from the tip sections of the better blades. Severe cracking produced by vibration was determined as the cause of failure. Several methods of overcoming the vibration problem are suggested.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-10-5-58E
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  • 87
    Publication Date: 2019-08-16
    Description: The design and experimental investigation of a 4.5-inch-mean-diameter two-stage turbine are presented herein and used to study the effect of size on the efficiency of turbines in the auxiliary power drive class. The results of the experimental investigation indicated that design specific work was obtained at design speed at a total-to-static efficiency of 0.639. At design pressure ratio, design static-pressure distribution through the turbine was obtained with an equivalent specific work output of 33.2 Btu per pound and an efficiency of 0.656. It was found that, in the design of turbines in the auxiliary power drive class, Reynolds number plays an important part in the selection of the design efficiency. Comparison with theoretical efficiencies based on a loss coefficient and velocity diagrams are presented. Close agreement was obtained between theory and experiment when the loss coefficient was adjusted for changes in Reynolds number to the -1/5 power.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-4-6-59E
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  • 88
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-08-14
    Description: The ram jet is basically one of the most dimple types of aircraft engine. It consists only of an inlet diffuser, a combustion system, and an exit nozzle. A typical ram-jet configuration is shown in figure 128. The engine operates on the Brayton cycle, and ideal cycle efficiency depends only on the ratio of engine to ambient pressure. The increased, engine pressures are obtained by ram action alone, and for this reason the ram jet has zero thrust at zero speed. Therefore, ram-jet-powered aircraft must be boosted to flight speeds close to a Mach number of 1.0 before appreciable thrust is generated by the engine. Since pressure increases are obtained by ram action alone, combustor-inlet pressures and temperatures are controlled by the flight speed, the ambient atmospheric condition, and by the efficiency of the inlet diffuser. These pressures and temperatures, as functions of flight speed and altitude, are shown in figure 129 for the NACA standard atmosphere and for practical values of diffuser efficiency. It can be seen that very wide ranges of combustor-inlet temperatures and pressures may be encountered over the ranges of flight velocity and altitude at which ram jets may be operated. Combustor-inlet temperatures from 500 degrees to 1500 degrees R and inlet pressures from 5 to 100 pounds per square inch absolute represent the approximate ranges of interest in current combustor development work. Since the ram jet has no moving parts in the combustor outlet, higher exhaust-gas temperatures than those used in current turbojets are permissible. Therefore, fuel-air ratios equivalent to maximum rates of air specific impulse or heat release can be used, and, for hydrocarbon fuels, this weight ratio is about 0.070. Lower fuel-air ratios down to about 0.015 may also be required to permit efficient cruise operation. This fuel-air-ratio range of 0.015 to 0.070 used in ram jets can be compared with the fuel-air ratios up to 0.025 encountered in current turbojets. Ram-jet combustor-inlet velocities range from 150 to 400 feet per second. These high linear velocities combined with the relatively low pressure ratios obtainable in ram jets require that the pressure drop through the combustor be kept low to avoid excessive losses in cycle efficiency. It has been estimated that, for a long-range ram-jet engine, an increase in pressure loss of one dynamic head would require a compensating 1-percent increase in combustion efficiency. Therefore, combustor pressure-loss coefficients (pressure drop/impact pressure) of the order of 1 to 4 are found in most current engines. The operating conditions described impose major problems in the design of stable and efficient ram-jet combustion systems. This chapter presents a survey of ram-jet combustor research and, where possible, points out criteria that may be useful in the design of ram-jet combustion systems.
    Keywords: Aircraft Propulsion and Power
    Type: Adaptation of Combustion Principles to Aircraft Propulsion. Volume II - Combustion in Air-Breathing Jet Engines
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  • 89
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-08-13
    Description: The performance of a jet power plant consisting of a compressor and a turbine is determined by the characteristic curves of these component parts and is controllable by the characteristics of the compressor and the turbine i n relation t o each other. The normal. output, overload, and throttled load of the Jet power plant are obtained on the basis of assumed straight-line characteristics.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-TM-1258
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  • 90
    Publication Date: 2019-08-15
    Description: The performance of turbine-engine combustors usually is given in terms of operating limits and combustion efficiency. The latter property is determined most often by measuring the increase in enthalpy across the combustor through the use of thermocouples. This investigation was conducted to determine the ability of gas-analytical techniques to provide additional information about combustor performance. Gas samples were taken at the outlet and two upstream stations and their compositions determined. In addition to over-all combustion efficiency, estimates of local fuel-air ratios, local combustion efficiencies, and heat-release rates can be made. Conclusions can be drawn concerning the causes of combustion inefficiency and may permit corrective design changes to be made more intelligently. The purpose of this investigation was not to present data for a given combustor but rather to show the types and value of additional information that can be gained from gas-analytical data.
    Keywords: Aircraft Propulsion and Power
    Type: NASA-MEMO-1-26-59E , E-245
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  • 91
    Publication Date: 2019-07-11
    Description: An investigation was conducted at simulated high-altitude flight conditions to evaluate the use of compressor evaporative cooling as a means of turbojet-engine thrust augmentation. Comparison of the performance of the engine with water-alcohol injection at the compressor inlet, at the sixth stage of the compressor, and at the sixth and ninth stages was made. From consideration of the thrust increases achieved, the interstage injection of the coolant was considered more desirable preferred over the combined sixth- and ninth-stage injection because of its relative simplicity. A maximum augmented net-thrust ratio of 1.106 and a maximum augmented jet-thrust ratio of 1.062 were obtained at an augmented liquid ratio of 2.98 and an engine-inlet temperature of 80 F. At lower inlet temperatures (-40 to 40 F), the maximum augmented net-thrust ratios ranged from 1.040 to 1.076 and the maximum augmented jet-thrust ratios ranged from 1.027 to 1.048, depending upon the inlet temperature. The relatively small increase in performance at the lower inlet-air temperatures can be partially attributed to the inadequate evaporation of the water-alcohol mixture, but the more significant limitation was believed to be caused by the negative influence of the liquid coolant on engine- component performance. In general, it is concluded that the effectiveness of the injection of a coolant into the compressor as a means of thrust augmentation is considerably influenced by the design characteristics of the components of the engine being used.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E52F20
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  • 92
    Publication Date: 2019-07-11
    Description: Internal performance of an XJ79-GE-1 variable ejector was experimentally determined with the primary nozzle in two representative after-burning positions. Jet-thrust and air-handling data were obtained in quiescent air for 4 selected ejector configurations over a wide range of secondary to primary airflow ratios and primary-nozzle pressure ratios. The experimental ejector data are presented in both graphical and tabulated form.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E57F25
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  • 93
    Publication Date: 2019-07-11
    Description: This report presents a compilation of static sea-level data on existing or designed American and British axial-flow turbojet engines in terms of basic engine parameters such as thrust and air flow. In the data presented, changes in the over-U engine performance with time sre examined as well as the relation of the various engine parameters to each other.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-51K29
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  • 94
    Publication Date: 2019-07-10
    Description: An investigation was made of the performance of nine conical cooling-air ejectors at primary jet pressure ratios from 1 to 10, secondary pressure ratios to 4.0, and a temperature ratio of unity. This phase of the investigation was limited to conical ejectors having shroud exit to primary nozzle exit diameter ratios of 1.06 and 1.40, with several spacing ratios for each. The experimental results indicated that the pumping range and amount of cooling-air flow obtained with a 1.06 diameter ratio ejector were relatively small for cooling purposes but that the maximum possible thrust loss, which occurred with no secondary flow, was only 7 percent of convergent nozzle thrust. The 1.40 diameter ratio ejector produced a large cooling air flow and showed a possible thrust loss of 29.5 percent with no cooling air flow. Thrust gains were attained with ejectors of both diameter ratios at secondary pressure ratios greater than 1.0. The limiting primary pressure ratio below which an ejector can operate at a specific secondary pressure ratio (cut-off point) may be estimated for various flight conditions from data contained herein.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E52F26
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  • 95
    Publication Date: 2019-09-20
    Description: The performance of a two-stage turbine with variable-area first-stage turbine nozzles was determined in the NACA Lewis altitude wind tunnel over a range of simulated altitudes from 15,000 to 44,000 feet and engine speeds from 50 to 100 percent of rated speed. The variable-area turbine nozzles used in this investigation were primarily a test device for compressor research purposes and were not necessarily of optimum aerodynamic design. The results of this investigation are indicative of effects of turbine-nozzle-area variation on turbine performance within the operating range allowed by the engine. The variable-area turbine nozzles were found to be mechanically reliable and to have negligible leakage losses. Increasing the turbine-nozzle-throat area from 1.15 to 1.67 square feet increased the corrected turbine gas flow or effective turbine nozzle area about 10 percent. At a given corrected turbine speed and turbine pressure ratio, changing the turbine nozzle area from 1.30 to 1. 67 square feet lowered the turbine efficiency 3 or 4 percent. The effect of increasing the turbine nozzle area from 1.15 to 1.67 square feet (decreasing the turning angle about 7 1/2 degrees) would be to lower the turbine efficiency about 5 or 6 percent.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E52J20
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  • 96
    Publication Date: 2019-07-11
    Description: Nine divergent-shroud ejector configurations were investigated to determine the effect of shroud divergence angle on ejector internal performance. Unheated dry air was used for both the primary and secondary flows. The decrease in the design-point thrust coefficient with increasing flow divergence angle (angle measured from primary exit to shroud exit) followed very closely a simple relation involving the cosine of the angle. This indicates that design-point thrust performance for divergent-shroud ejectors can be predicted with reasonable accuracy within the range investigated. The decrease in design-point thrust coefficient due to increasing the flow divergence engle from 120deg to 30deg (half-singles) was approximately 6 percent. Ejector air-handling characteristics and the primary-nozzle flow coefficient were not significantly affected by change in shroud divergence angle.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E57F13
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  • 97
    Publication Date: 2019-07-11
    Description: Performance data obtained with recording oscillographs are presented to show the transient response of the General Electric Integrated Electronic Control operating on the J47 RXl-3 turbo-Jet engine over a range of altitudes from 10,000 to 45,000 feet and at ram pressure ratios of 1.03 and 1.4. These data represent the performance of the final control configuration developed after an investigation of the engine transient behavior in the NACA altitude wind tunnel. Oscillograph traces of controlled accelerations (throttle bursts),oontrolled decelerations (throttle chops), and controlled altitude starts are presented.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE50G12
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  • 98
    Publication Date: 2019-07-11
    Description: A two-spool turbojet engine was operated in the Lewis altitude wind tunnel to study the inception of compressor surge. In addition to the usual steady-state pressure and temperature measurements, the compressors were extensively instrumented with fast-response interstage pressure transducers. Thus it was possible to obtain maps for both compressors, pressure oscillations during rotating stall, effects of stall on efficiency, and stage-loading curves. In addition, with the transient measurements, it was possible to record interstage pressures and then compute stage performance during accelerations to the stall limit. Rotating stall was found to exist at low speeds in the outer spool. Although the stall arose from poor flow conditions at the inlet-stage blade tips, the low-energy air moved through the machine from the tip at the inlet to the outer spool to the hub at the inlet to the inner spool. This tip stall ultimately resulted in compressor surge in the mid-speed region, and necessitated inter-compressor air bleed. Interstage pressure measurements during acceleration to the compressor stall limit indicated that rotating stall was not a necessary condition for compressor surge and that, at the critical stall point, the circumferential interstage pressure distribution was uniform. The exit-stage group of the inner spool was first t o stall; then, the stages upstream stalled in succession until the inlet stage of the outer spool was stalled. With a sufficiently high fuel rate, the process repeated with a cycle time of about 0.1 second. It was possible to construct reproducible stage stall lines as a function of compressor speed from the stage stall points of several such compressor surges. This transient stall line was checked by computing the stall line from a steady-state stage-loading curve. Good agreement between the stage stall lines was obtained by these two methods.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-E57I27
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  • 99
    Publication Date: 2019-07-11
    Description: A method has been developed for modifying a rocket motor so that its exhaust characteristics simulate those of a turbojet engine. The analysis necessary to the design is presented along with tests from which the designs are evaluated. Simulation was found to be best if the exhaust characteristics to be duplicated were those of a turbojet engine at high altitudes and with the afterburner operative.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-L54I15
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  • 100
    Publication Date: 2019-07-11
    Description: A modified J33-A-27 compressor was operated over a range of equivalent impeller speeds from 6100 to 13,250 rpm in order to obtain the over-all compressor performance. At the equivalent design speed of 11,800 rpm, the maximum efficiency of 0.764 and peak pressure ratio of 4.56 occurred at an equivalent weight flow of 104.07 pounds per second. At the highest equivalent speed (13,250 rpm) a maximum efficiency of 0.711, a maximum equivalent weight flow of 123.00 pounds per second, and a peak pressure ratio of 5.76 were obtained.
    Keywords: Aircraft Propulsion and Power
    Type: NACA-RM-SE50D25
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