ALBERT

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) -;

Description: Zusammenfassung der Erkenntnisse über die kritischen Witterungsperioden, die einen Befall mit Phytophthora infestans begünstigen. Die benötigten Temperatur- und Feuchtebedingungen im Bestand werden auf die benötigten Bedingungen in Klimahütten übertragen. Für eine kritische Periode werden 88% Luftfeuchte bei 12-16°C für mindestens 15 Stunden gefolgt von einer 12 stündigen Periode nach der Infektion mit ca. 20°C benötigt. KATASTER-BESCHREIBUNG: hohe Boden- und Luftfeuchte + & warme Witterung + -〉 Infektionsgefahr mit Phytophthora steigt + KATASTER-DETAIL: "Bestandsfeuchteregel" Zusammenhang zwischen Witterung und Ausbreitung der Phytophtora

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

Description: Es werden Häufigkeiten der phytophthorakritischen Witterungsperioden nach der "Temperatur-Feuchte-Regel" und der "Dampfdruckregel" in Bayern berechnet. Die Anwendbarkeit beider Regeln wird im Vergleich mit Befallsmeldungen validiert. Zudem wird ein neuer Schwellwertansatz, die "Bestandesfeuchteregel" zur Identifizierung kritischer Perioden vorgestellt und anhand zahlreicher Beispiele validiert. Auch auf das Nulldatum als frühest möglicher Befallszeitpunkt wird eingegangen. KATASTER-BESCHREIBUNG: Schwellwertansatz zur Identifizierung phytophthorakritischer Witterungsperioden KATASTER-DETAIL: Kritische Periode liegt vor, wenn folgende Bedingungen alle erfüllt sind: - T(Nacht) = 10-13°C (so daß sich Tau niederschlagen kann) - T(Tag) = 20-23°C - die Taupunktsdifferenz an 6 von 8 dreistündlichen Terminen 〈= 2°C beträgt oder an 5 von 8 dreistündlichen Terminen 〈= 2°C beträgt und direkt danach eine regenfeuchte Periode folgt oder direkt davor, mit maximal einem Termin der Taupunktsdifferenz 〉 2°C, eine regenfeuchte Periode liegt

Description: Measurements of the statistical properties of the fluctuating wall pressure produced by a subsonic turbulent boundary layer are described. The measurements provide additional information about the structure of the turbulent boundary layer; they are applicable to the problems of boundary-layer induced noise inside an airplane fuselage and to the generation of waves-on water. The spectrum of the wall pressure is presented in dimensionless form. The ratio of the root-mean-square wall pressure to the free-stream dynamic pressure is found to be a constant square root of bar P(sup 2)/q(sub infinity) = 0.006 independent of Mach number and Reynolds number. In addition, space- time correlation measurements in the stream direction show that pressure fluctuations whose scale is greater than or equal to 0.3 times the boundary-layer thickness are convected with the convection speed U(sub c) = 0.82U(sub infinity) where U(infinity) is the free-stream velocity and have lost their identity in a distance approximately equal to 10 boundary-layer thicknesses.

Description: Approximate analytical solutions are presented for two-dimensional and axisymmetric hypersonic flow over slender power law bodies. Both zero order (M approaches infinity) and first order (small but nonvanishing values of 1/(M(Delta)(sup 2) solutions are presented, where M is free-stream Mach number and Delta is a characteristic slope. These solutions are compared with exact numerical integration of the equations of motion and appear to be accurate particularly when the shock is relatively close to the body.

Description: An experimental investigation of the mixing of two coaxial gas streams was conducted over a range of subsonic jet Mach numbers and temperatures. Three configurations were investigated. One had no innerbody in the primary or inner pipe and was designed to give flat velocity profiles at the exit of the primary pipe. The other two configurations had innerbodies in the primary pipe. These were designed to give velocity profiles similar to those existing at the inlet of propulsive systems such as afterburners. Curves of axial velocity and temperature profiles across the radius are presented at various axial stations. For the two configurations with the innerbody, data are shown at stations out to approximately 8 primary-pipe diameters from the exit of the primary pipe. For the flat-velocity-profile configuration, data are shown at distances extending downstream at 22 primary-pipe diameters from the exit of the primary pipe.

Description: Techniques which have been used for finishing and quantitatively specifying surface roughness on boundary-layer-transition models are reviewed. The appearance of a surface as far as roughness is concerned can be misleading when viewed either by the eye or with the aid of a microscope. The multiple-beam interferometer and the wire shadow method provide the best simple means of obtaining quantitative measurements.

Description: Wind-tunnel tests have been made to determine the location of the boundary-layer transition on three hemispheres having surface roughness (absolute) values of 50, 580, and 2760 microinches. After the initial test run of the smoothest (50 microinch) hemisphere, holes ranging in depth from 1500 to 2500 microinches were noticed in the meridian where transition was observed. The holes were believed to be caused by particles in the air stream. Shadowgraph pictures were obtained of all hemispheres and surface temperature measurements were made on one hemisphere (580 microinches). Tests at high Reynolds numbers (6.4 to 7.5 x 10(exp 6) and a Mach number of 2.48 did not indicate any transition on the 50-microinch surface hemisphere before the holes appeared. However, after the holes were noticed, transition locations as low as 50 deg(measured from the stagnation point) were observed at similar Reynolds numbers and Mach numbers. It is felt the transition resulted from the holes. Similar transition locations of approximately 500 were also observed in the tests of hemispheres with surface roughness values of 580 and 2760 microinches at high Reynolds numbers (6.4 x 10(exp 6) to 7.5 x 10(exp 6)) and at a Mach number of 2.48. The results at a Mach number of 2.48 indicate that an absolute surface roughness value of 50 microinches was not critical in causing boundary-layer tran sition at Reynolds numbers of 6.4 to 7.5 x 10(exp 6) whereas roughness values of 580 and 2760 microinches were greater than critical. Transition Reynolds numbers based on momentum thickness, R(sub phi T) varied over a range of approximately 480 to 300 for transition locations, alpha, on the hemisphere from 880 to 410 (measured from the stagnation point). A maximum value of R(phi) of 660 (based on alpha = 90 deg) was obtained with the 50-microinch surface hemisphere at a Mach number of 2.48.