ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • PROPULSION SYSTEMS  (1,456)
  • 1970 - 1974  (1,456)
Collection
Years
Year
  • 1
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2012-05-22
    Description: The severity of proposed noise goals for STOL systems has resulted in a new design approach for aircraft propulsion systems. It has become necessary to consider the influence of the noise goal on the design of engine components, engine systems, and the integrated nacelle, separately and collectively, from the onset of the design effort. This integrated system design approach is required in order to effect an optimization of the propulsion and aircraft system. Results from extensive design studies and pertinent test programs are presented which show the effect of noise specifications on component and system design, and the trade-offs possible of noise versus configuration and performance. The design optimization process of propulsion systems for powered lift systems is presented beginning with the component level and proceeding through to the final integrated propulsion system. Designs are presented which are capable of meeting future STOL noise regulations and the performance, installation and economic penalties are assessed as a function of noise level.
    Keywords: PROPULSION SYSTEMS
    Type: AGARD V(STOL Propulsion Systems; 17 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2012-05-22
    Description: Two aspects of the dispersion of pollutants from aircraft are reviewed. The first is the dispersal of aircraft exhaust emissions in the vicinity of airports; the second is the dispersal of exhaust trails in the upper atmosphere. Techniques available for modeling this dispersal and how they might be applied to the airport problem are discussed. Field studies of airport pollution are then reviewed to assess current pollutant levels around airports and the aircraft's contribution to those levels. The possibility of contrail formation from jet emissions at high altitude is then considered and the effect of uncertainties in the trial mixing processes evaluated.
    Keywords: PROPULSION SYSTEMS
    Type: AGARD The Fluid Dynamics Aspects of Air Pollution Related to Aircraft Operations; p 5-16
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: An experimental test program was performed to demonstrate the durability of a beryllium INTEREGEN rocket engine when operating under conditions simulating the space shuttle reaction control system. A vibration simulator was exposed to the equivalent of 100 missions of X, Y, and Z axes random vibration to demonstrate the integrity of the recently developed injector-to-chamber braze joint. An off-limits engine was hot fired under extreme conditions of mixture ratio, chamber pressure, and orifice plugging. A durability engine was exposed to six environmental cycles interspersed with hot-fire tests without intermediate cleaning, service, or maintenance. Results from this program indicate the ability of the beryllium INTEREGEN engine concept to meet the operational requirements of the space shuttle reaction control system.
    Keywords: PROPULSION SYSTEMS
    Type: R-9557 , NASA-CR-140308
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2013-08-31
    Description: An evaluation of the technology and the development of a preliminary design for a 25 kilowatt solar array system for solar electric propulsion are discussed. The solar array has a power to weight ratio of 65 watts per kilogram. The solar array system is composed of two wings. Each wing consists of a solar array blanket, a blanket launch storage container, an extension/retraction mast assembly, a blanket tensioning system, an array electrical harness, and hardware for supporting the system for launch and in the operating position. The technology evaluation was performed to assess the applicable solar array state-of-the-art and to define supporting research necessary to achieve technology readiness for meeting the solar electric propulsion system solar array design requirements.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-120483 , LMSC-D384250
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: The technology status of 8 cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5 cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8 cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71611 , AIAA PAPER 74-1116 , AIAA/SAE 10th Propulsion Conf.; 21-23 Oct. 1974; San Diego, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2013-08-31
    Description: A two-dimensional inlet and a turbojet engine were investigated in a Mach 0.4 stream so as to ingest the tip vortex of a forward mounted wing. Results show that ingestion of a wing tip vortex by a turbojet engine can cause a large reduction in engine stall margin. The loss in stall compressor pressure ratio was primarily dependent on vortex location and rotational direction and not on total-pressure variations across the compressor face.
    Keywords: PROPULSION SYSTEMS
    Type: E-8091 , NASA-TM-X-71610
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2013-08-31
    Description: The operational flight instrumentation required for performance monitoring and fault detection are presented. Measurements by the burn through monitors are presented along with manifold and helium source pressures.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-140258 , LEC-3594 , JSC-09130
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2013-08-31
    Description: A three-dimensional finite element elasto-plastic strain analysis was performed for the throat section of a regeneratively cooled rocket combustion chamber. The analysis employed the RETSCP finite element computer program. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the chamber operating cycle. The analysis was performed for chamber configuration and operating conditions corresponding to a hydrogen-oxygen combustion chamber which was fatigue tested to failure. The computed strain range at typical chamber operating conditions was used in conjunction with oxygen-free, high-conductivity (OHFC) copper isothermal fatigue test data to predict chamber low-cycle fatigue life.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134641-VOL-1
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2013-08-31
    Description: Several unique techniques and related devices are described which are in use at the Lewis Research Center for off-design testing of fan and compressor sections in full-scale jet engines. The devices presented permit a wide range of experimental conditions and minimize downtime for hardware changes. The techniques involve use of such devices as inlet pressure distortion jets, a hydrogen burner for inlet temperature distortions, fan back pressure jets to simulate a variable area nozzle, and either an inflow-outflow bleed system or a fuel spurt system to alter compressor discharge pressure.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71597 , E-8062 , Aerospace Engr. and Manuf. Meeting; 30 Sep. - 3 Oct. 1974; San Diego, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2013-08-31
    Description: The analytic models developed for computing the periodic sound pressure of subsonic fans and compressors in an infinite, hardwall annular duct with uniform flow are described. The basic sound-generating mechanism is the scattering into sound waves of velocity disturbances appearing to the rotor or stator blades as a series of harmonic gusts. The models include component interactions and rotor alone.
    Keywords: PROPULSION SYSTEMS
    Type: D6-43296-1 , NASA-CR-132443
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2013-08-31
    Description: An experimental wind tunnel investigation was conducted to determine the effects of time-variant distortions produced in a supersonic inlet on a J85-GE-13 turbojet engine. Results are presented principally in terms of instantaneous distortion amplitudes and total-pressure contours measured through compressor stall. They indicate that, although a time-averaged distortion may be far from a stall-inducing value, corresponding instantaneous distortion amplitudes can approach or exceed this value. Seven engine stall events were studied. In six of these events instantaneous distortion peaks of sufficient magnitude to cause stall were observed in the time period shortly before stall was detected.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3002 , E-6294
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2013-08-31
    Description: At the relatively high takeoff speeds of supersonic transport aircraft, an important question concerns whether the flight speed affects the noise of suppressor nozzles. To answer this question, flyover and static tests using a modified F-106B aircraft were conducted on a 104-tube suppressor nozzle. Comparison of adjusted flyover and static spectra indicated that flight velocity had a small adverse effect on the suppression of the 104-tube suppressor. The adverse effect was larger with the acoustic shroud installed than without it.
    Keywords: PROPULSION SYSTEMS
    Type: E-7901 , NASA-TM-X-3049
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: A research program was conducted to define the level of the current technology base for reaction control system rocket engines suitable for space shuttle applications. The project consisted of engine analyses, design, fabrication, and tests. The specific objectives are: (1) extrapolating current engine design experience to design of an RCS engine with required safety, reliability, performance, and operational capability, (2) demonstration of multiple reuse capability, and (3) identification of current design and technology deficiencies and critical areas for future effort.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134336 , REPT-8701-910041
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2013-08-31
    Description: The results of an airline study of the economic effects of propulsion system technology on current and future transport aircraft are presented. This report represents the results of a detailed study of propulsion system operating economics. The study has four major parts: (1) a detailed analysis of current propulsion system maintenance with respect to the material and labor costs encountered versus years in service and the design characteristics of the major elements of the propulsion system of the B707, b727, and B747. (2) an analysis of the economic impact of a future representative 1979 propulsion system is presented with emphasis on depreciation of investment, fuel costs and maintenance costs developed on the basis of the analysis of the historical trends observed. (3) recommendations concerning improved methods of forecasting the maintenance cost of future propulsion systems are presented. A detailed method based on the summation of the projected labor and material repair costs for each major engine module and its installation along with a shorter form suitable for quick, less detailed analysis are presented, and (4) recommendations concerning areas where additional technology is needed to improve the economics of future commercial propulsion systems are presented along with the suggested economic benefits available from such advanced technology efforts.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134645
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2013-08-31
    Description: Recently advanced simulation techniques have been developed for the digital computer and used as the basis for development of a generalized dynamic engine simulation computer program, called DYNGEN. This computer program can analyze the steady state and dynamic performance of many kinds of aircraft gas turbine engines. Without changes to the basic program DYNGEN can analyze one- or two-spool turbofan engines. The user must supply appropriate component performance maps and design-point information. Examples are presented to illustrate the capabilities of DYNGEN in the steady state and dynamic modes of operation. The analytical techniques used in DYNGEN are briefly discussed, and its accuracy is compared with a comparable simulation using the hybrid computer. The impact of DYNGEN and similar all-digital programs on future engine simulation philosophy is also discussed.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71552 , E-7968 , Propulsion and Energetics Meeting; 9-13 Sep. 1974; Ankara
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 2013-08-31
    Description: A single-stage axial-flow turbine was investigated to determine the effect of increased stator throat area on the performance level of a turbojet engine turbine. The stator blades were bent to increase the throat area in order to move the compressor operating point in the engine farther away from surge. Results are compared with those obtained with the as-cast stator setting.
    Keywords: PROPULSION SYSTEMS
    Type: E-7776 , NASA-TN-D-7626
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2013-08-31
    Description: A summary is presented of an acoustic test program for investigating engine noise suppression and jet/flap interaction noise associated with an EBF STOL powered lift system. A highly suppressed TF-34 engine and EBF wing were used in the investigation. The engine was suppressed 21 PndB to a level of 94 PndB. An UTW powered lift system was tested with conventional, mixer, and decayer-type nozzles. The configuration with velocity decayer nozzle and acoustically treated shroud had the lowest noise (98 PndB). An OTW configuration with non-decayer nozzle was about 10 db quieter than the corresponding UTW system. UTW and OTW noise data are compared with scale model correlations.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71539 , E-7946 , Air Transport Meeting; 30 Apr. - 2 May 1974; Dallas
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2013-08-31
    Description: Some of the mutual aircraft afterbody and engine nozzle interferences that can exist on aircraft complex aft-ends and on simplified twin-jet afterbodies are reviewed. Emphasis is placed on studies of twin-engine fuselage configurations with nozzles installed near the terminus of the afterbody where the interactions of the nozzle exhausts and external stream produce a complex flow-field environment. The magnitude of the aft-end problem for real aircraft configurations is illustrated, and some theoretical and empirical considerations of afterbody drag on simple bodies are treated. Many of the factors regarding airframe-installation effects on nozzle performance are discussed, as well as nozzle-installation effects on aircraft performance.
    Keywords: PROPULSION SYSTEMS
    Type: L-9283 , NASA-TN-D-7525
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2013-08-31
    Description: This report describes HYDES, a hybrid computer program capable of simulating one-spool turbojet, two-spool turbojet, or two-spool turbofan engine dynamics. HYDES is also capable of simulating two- or three-stream turbofans with or without mixing of the exhaust streams. The program is intended to reduce the time required for implementing dynamic engine simulations. HYDES was developed for running on the Lewis Research Center's Electronic Associates (EAI) 690 Hybrid Computing System and satisfies the 16384-word core-size and hybrid-interface limits of that machine. The program could be modified for running on other computing systems. The use of HYDES to simulate a single-spool turbojet and a two-spool, two-stream turbofan engine is demonstrated. The form of the required input data is shown and samples of output listings (teletype) and transient plots (x-y plotter) are provided. HYDES is shown to be capable of performing both steady-state design and off-design analyses and transient analyses.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3014 , E-7316
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2013-08-31
    Description: An experimental investigation was conducted to determine the thermal effectiveness of an aluminized Mylar-silk net insulation system containing up to 160 layers. The experimentally measured heat flux was compared with results predicted by using (1) a previously developed semi-empirical equation and (2) an effective-thermal-conductivity value. All tests were conducted at a nominal hot-boundary temperature of 294 K (530 R) with liquid hydrogen as the heat sink. The experimental results show that the insulation performed as expected and that both the semi-empirical equation and effective thermal conductivity of a small number of layers were adequate in predicting the thermal performance of a large number of layers of insulation.
    Keywords: PROPULSION SYSTEMS
    Type: E-7815 , NASA-TN-D-7659
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2013-08-31
    Description: Experimental results of a series of engine tests designed to obtain the stage dynamics of an eight-stage axial-flow compressor over the frequency range of 0.5 to 200 hertz are presented. The total pressure at the compressor face was varied by means of a secondary air jet system installed in the engine inlet and positioned to oppose the primary airflow. Total-pressure probes located at each compressor stage were used to obtain the frequency response of each compressor-stage total pressure to the average compressor-inlet total pressure. The engine operating conditions were chosen to illustrate the effects of changing the rotor speed, changing the exhaust nozzle area, and isolating the compressor discharge pressure perturbations from the fuel control and hence, the fuel flow.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3012 , E-7709
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Publication Date: 2013-08-31
    Description: The ability of analysis to predict ejector nozzle characteristics over a wide range of conditions and to study the relation between design parameters and performance is assessed. The analytical method investigated provided an accurate and economical method for predicting the performance of supersonic ejector nozzles. The factors which had the greatest influence over ejector nozzle behavior were those which influenced the initial expansion and recompression process.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7601 , E-7413
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Publication Date: 2013-08-31
    Description: A low-power MPD thruster with downstream cathode was tested for endurance with a series of hollow cathode designs. Failure modes and failure mechanisms were identified. A new hollow cathode (with rod inserts) has emerged which shows promise for long life. The downstream positioning of the cathode was also changed from an on-axis location to an off-axis location. Data are presented for a 1332-hour life test of this new hollow cathode located at the new off-axis location. Xenon propellant was used.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7616 , E-7647
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 2013-08-31
    Description: An analytical procedure for computing the performance of supersonic ejector nozzles is presented. This procedure includes real sonic line effects and an interaction analysis for the mixing process between the two streams. The procedure is programmed in FORTRAN 4 and has operated successfully on IBM 7094, IBM 360, CDC 6600, and Univac 1108.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7602 , E-7476
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Publication Date: 2013-08-31
    Description: The results of a program of experimental and analytical research in casing treatments over axial compressor rotor blade tips are presented. Circumferential groove, axial-skewed slot, and blade angle slot treatments were tested. These yielded, for reduction in stalling flow and loss in peak efficiency, 5.8% and 0 points, 15.3% and 2.0 points, and 15.0% and 1.2 points, respectively. These values are consistent with other experience. The favorable stalling flow situations correlated well with observations of higher-then-normal surface pressures on the rotor blade pressure surfaces in the tip region, and with increased maximum diffusions on the suction surfaces. Annular wall pressure gradients, especially in the 50-75% chord region, are also increased and blade surface pressure loadings are shifted toward the trailing edge for treated configurations. Rotor blade wakes may be somewhat thinner in the presence of good treatments, particularly under operating conditions close to the baseline stall.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134552 , R73AEG326
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2013-08-31
    Description: Methods of handling one-third-octave band noise data originating from the outdoor full-scale fan noise facility and the engine acoustic facility at the Lewis Research Center are presented. Procedures for standardizing, retrieving, extrapolating, and reporting these data are explained. Computer programs are given which are used to accomplish these and other noise data analysis tasks. This information is useful as background for interpretation of data from these facilities appearing in NASA reports and can aid data exchange by promoting standardization.
    Keywords: PROPULSION SYSTEMS
    Type: E-7609 , NASA-TM-X-3013
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2013-08-31
    Description: Experimental results of a three-stage highly loaded fan drive turbine test program are presented. A plain blade turbine, a tandem blade turbine, and a tangentially leaned stator turbine were designed for the same velocity diagram and flowpath. Seven combinations of bladerows were tested to evaluate stage performances and effects of the tandem blading and leaned stator. The plain blade turbine design point total-to-total efficiency was 0.886. The turbine with the stage three leaned stator had the same efficiency with an improved exit swirl profile and increased hub reaction. Two-stage group tests showed that the two-stage turbine with tandem stage two stator had an efficiency of 0.880 compared to 0.868 for the plain blade two-stage turbine.
    Keywords: PROPULSION SYSTEMS
    Type: R73AEG154 , NASA-CR-2362
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2013-08-31
    Description: Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.
    Keywords: PROPULSION SYSTEMS
    Type: E-7822 , NASA-TM-X-71509 , Conf. on Climatic Impact Assessment Program; 26 Feb. - 1 Mar. 1974; Cambridge, MA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Publication Date: 2013-08-31
    Description: A program to identify surplus solid rocket propellant engines which would be available for a program of functional integrity testing was conducted. The engines are classified as: (1) upper stage and apogee engines, (2) sounding rocket and launch vehicle engines, and (3) jato, sled, and tactical engines. Nearly all the engines were available because their age exceeds the warranted shelf life. The preference for testing included tests at nominal flight conditions, at design limits, and to establish margin limits. The principal failure modes of interest were case bond separation and grain bore cracking. Data concerning the identification and characteristics of each engine are tabulated. Methods for conducting the tests are described.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-136864
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2013-08-31
    Description: Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.
    Keywords: PROPULSION SYSTEMS
    Type: L-9363 , NASA-TN-D-7567
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Publication Date: 2013-08-31
    Description: Results from experimental work on model scale cascade reversers with cold airflow are presented. Sound power level directivity and spectral characteristics for cascade reversers are reported. Effect of cascade exit area ratio, vane profile shape, and emission arc are discussed. Model equivalent diameters varied from 3 to 5 inches, pressure ratios range from 1.15 to 3.0. Depending on the reverser type, acoustic power was proportional to the 4 1/2 to 6th power of ideal jet velocity. Reverser noise peaked at higher frequency and was more omnidirectional than nozzle-alone jet noise. Appreciable reduction in sideline noise was obtained from plane shields. Airfoil-vaned cascades were the most aerodynamically efficient and least noisy reversers. Scaling of cascade reverser data to example aircraft engines showed all cascades above the 95 PNdB sideline goal from STOL aircraft. However, the airfoil-vaned reverser has a good potential for meeting this goal for high-bypass (low pressure ratio) exhausts.
    Keywords: PROPULSION SYSTEMS
    Type: E-7864 , NASA-TM-X-71500 , Aerospace Sci. Meeting; 30 Jan. - 1 Feb. 1974; Washington, DC; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Publication Date: 2013-08-31
    Description: Several variations of a boattailed shroud for a 10 deg conical plug nozzle were tested using an F-106B aircraft for Mach 0.6 to 1.3. The data were obtained so that the tradeoff between boattail and plug size could be studied for an underwing nacelle location. The nozzles were tested with J85-GE-13 turbojet engine, and the data were compared to previous flight results of installed plug nozzles. Boattail area varied from 31 to 66 percent of the nacelle area. The effect of increasing projected boattail area was to increase the gross thrust coefficient in the same way as from isolated data for flight Mach numbers below 0.85. The highest gross thrust coefficient (0.958) was obtained at Mach 0.95 with a long circular arc shroud configuration with a very small amount of secondary air flow.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-2983 , E-7612
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2016-03-07
    Description: A solid propellant composition of improved efficiency is described which includes an oxidizer containing ammonium perchlorate, and a powered metal fuel, preferably aluminum or beryllium, in the form of a composite. The metal fuel is contained in the crystalline lattice framework of the oxidizer, as well as within the oxidizer particles, and is disposed in the interstices between the oxidizer particles of the composition. The propellant composition is produced by a process comprising the crystallization of ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal with the particles of oxidizer containing occluded metal.
    Keywords: PROPULSION SYSTEMS
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Publication Date: 2013-08-31
    Description: Translating lip, axisymmetric inlets have been tested at freestream Mach numbers between 0.0 and 0.30 and at angles of attack between 0 and 90 degrees. Three isolated inlet models were tested. One model represented the inlet geometry at cruise, that is, with no lip translation. The other two models had forward translating lips with different contours. The low forward speed inlet angle-of-attack capability with the translating lip was increased more than twenty degrees over the basic untranslated lip configuration at the higher inlet airflows. The static inlet performance with the translating lip was also greatly improved. The design translation distance, defined by potential flow analysis, was near optimum.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-2467
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: The experimental results are summarized that were obtained in the development of a Teflon solid propellant pulsed plasma thruster. The feasibility was established of storing and feeding solid propellant in the form of an open circular loop into an operational thruster. This technique was verified to be practical by feeding over 20 inches of Teflon into a micro-thruster over an accumulated life test of 1858 hours. High energy density capacitors were evaluated under vacuum conditions when the capacitor is coupled directly to a plasma thruster. Numerous early capacitor failures were encountered. It was concluded that essentially all of the failures encountered in a vacuum environment are due to an internal electrical breakdown that will occur inside a capacitor that is not truly hermetically sealed. A steady input power significantly in excess of 130 watts can safely be tolerated if heat conduction can be provided to a sink whose temperature is about 16 C. A vacuum life test of the capacitor bank was carried out while discharging into a milli-lb. (milli-Newton) type pulsed plasma thruster. More than 1500 hours of vacuum testing of this milli-Newton type system has been accumulated without any capacitor problems. Recommendations are made for future capacitor designs.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-139272 , MS172R0001
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Publication Date: 2013-08-31
    Description: Computer programs for analyzing the acoustic properties of turbomachinery with ducted flow were developed. The models include component interactions and rotor alone. Test case results determined from the computer programs are presented.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-132445 , D6-43296-3
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Publication Date: 2013-08-31
    Description: Analytical models were developed for computing the periodic sound pressures of subsonic fans in an infinite hardwall annular duct with uniform flow. The computer programs are described which are used for numerical computations of sound pressure mode amplitudes. The data are applied to the acoustic properties of turbomachinery.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-132444 , D6-43296-2
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: A study program for conceptual design studies of remote lift and lift/cruise fan systems to meet the requirements of military V/STOL aircraft was conducted. Parametric performance and design data are presented for fans covering a range of pressure ratios, including both single and two stage fan concepts. The gas generator selected for these fan systems was the J101-GE-100 engine. Noise generation and transient response were determined for selected fan systems.
    Keywords: PROPULSION SYSTEMS
    Type: R74AEG283 , NASA-CR-134636
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Publication Date: 2013-08-31
    Description: The performance and heat transfer characteristics of a doublet element type injector for the space shuttle orbiter maneuvering engine thrust chamber were investigated. Ths stability characteristics were evaluated over a range of chamber pressures and mixture ratios. The specific objectives of the test were: (1) to determine whether stability has been influenced by injection of boundary layer coolant across the cavity entrance, (2) if the injector is stable, to determine the minimum cavity area required to maintain stability, and (3) if the injector is unstable, to determine the effects of entrance geometry and increased area on stability.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134359 , ASR74-204
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 2013-08-31
    Description: Results of an experimental program conducted on a mixed-compression inlet coupled to a turbofan engine are presented. Open-loop frequency response data are presented that show the response of shock position (as measured by an average inlet static pressure) to sinusoidal airflow disturbances produced at the compressor face station. Also presented are results showing the effect of different passive terminations (a choke plate or a long duct) on the characteristics of the inlet. Transfer functions obtained by using experimental data are presented and compared to the experimental data. Closed-loop frequency response of shock position (with a proportional-plus-integral controller) is presented. In addition, transient data are presented that show the unstart-restart characteristics of the inlet.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3104 , E-7924
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: This study had the objectives of determining the most promising conventional and variable cycle engine types; the effect of design cruise Mach number (2.2, 2.7 and 3.2) on a commercial supersonic transport; effect of advanced engine technology on the choice of engine cycle; and effect of utilizing hydrogen as the engine fuel. The technology required for the engines was defined, and the levels of development to ensure availability of this technology in advanced aircraft propulsion systems were assessed. No clearcut best conventional or variable cycle engine was identified. The dry bypass turbojet and the duct burning turbofans were initially selected as the best conventional engines, but later results, utilizing augmentation at takeoff, added the mixed-flow augmented turbofan as a promising contender. The modulating air flow, three-rotor variable cycle engine identified the performance features desired from VCE concepts (elimination of inlet drag and reduction in afterbody drag), but was a very heavy and complex engine.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-143634 , R74AEG330
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Publication Date: 2013-08-31
    Description: The use of heat conduction flame generated in a premixed supersonic stream is discussed. It is shown that the flame is controlled initially by heat conduction and then by chemical reaction. Such a flame is shorter than the diffusion type of flame and therefore it requires a much shorter burner. The mixing is obtained by injecting the hydrogen in the inlet. Then the inlet can be cooled by film cooling.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-132446
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 2013-08-31
    Description: A comprehensive summary of the results of a cold-flow and hot-fire experimental study of the mixing and atomization characteristics of injector elements incorporating noncircular orifices is presented. Both liquid/liquid and gas/liquid element types are discussed. Unlike doublet and triplet elements (circular orifices only) were investigated for the liquid/liquid case while concentric tube elements were investigated for the gas/liquid case. It is concluded that noncircular shape can be employed to significant advantage in injector design for liquid rocket engines.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134315 , R-9271
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2013-08-31
    Description: Aspects of the development and characteristics of thermal shock resistant hafnia ceramic material for use in solid propellant rocket nozzles are presented. The investigation of thermal shock resistance factors for hafnia based composites, and the preparation and analysis of a model of elastic materials containing more than one crack are reported.
    Keywords: PROPULSION SYSTEMS
    Type: QPR-12 , NASA-CR-138804
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2013-08-31
    Description: The combustion characteristics of hypergolic propellants are described. A research project was conducted to determine if the reaction control system engine propellants on Apollo spacecraft undergo explosive reaction when subjected to conditions present in the engine at the time of ignition. Combustion characteristics pertinent to the hard-start phenomenon are considered. The thermal stability of frozen mixtures of hydrazine-based fuels with nitrogen tetroxide was analyzed. Results of the tests are presented in the form of tables and graphs.
    Keywords: PROPULSION SYSTEMS
    Type: BM-IR-1646-VOL-2 , NASA-CR-134314
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: The JT8D turbofan engine, widely used in short and medium range transport aircraft, contributes substantially to airport community noise. The jet noise is predominant in the JT8D engine and may be reduced in a modified engine, without loss of thrust, by increasing the airflow to reduce jet velocity. A configuration study evaluated the effects of fan airflow, fan pressure ratio, and bypass ratio on noise, thrust, and fuel comsumption. The cycle selected for the modified engine was based upon an increased diameter, single-stage fan and two additional core engine compressor stages, which replace the existing two-stage fan. Modifications were also made to the low pressure turbine to provide the increased torque required by the larger diameter fan. The resultant JT8D-100 engine models have the following characteristics at take-off thrust, compared to the current JT8D engine: Airflow and bypass ratio are increased, and fan pressure ratio and engine speed are reduced. The resultant engine is also longer, larger in diameter, and heavier than the JT8D base model, but these latter changes are compensated by the increased thrust and decreased fuel comsumption of the modified engine, thus providing the capability for maintaining the performance of the current JT8D-powered aircraft.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134654 , PWA-4790
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Publication Date: 2013-08-31
    Description: A 24.70-cm(9.72-in.) tip diameter single-stage, axial-flow turbine was designed for a turbojet engine. Cold-air tests were made over a range of speeds from 30 to 105 percent of design equivalent speed and over a range of total-pressure ratios from 1.30 to 2.66. Results are presented in terms of specific work, torque, mass flow, and efficiency.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7625 , E-7754
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Publication Date: 2013-08-31
    Description: Test hardware, facilities, and procedures are described along with results of electrically heated tube and channel tests conducted to determine adverse operating condition limits for convectively cooled chambers typical of Space Shuttle Orbit Manuevering Engine designs. Hot-start tests were conducted with corrosion resistant steel and nickel tubes with both monomethylhydrazine and 50-50 coolants. Helium ingestion, in both bubble and froth form, was studied in tubular test sections. Helium bubble ingestion and burn-out limits in rectangular channels were also investigated.
    Keywords: PROPULSION SYSTEMS
    Type: ASR-74-131 , NASA-CR-134282
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Publication Date: 2013-08-31
    Description: Results are presented of a cold-flow and hot-fire experimental study of the mixing and atomization characteristics of injector elements incorporating noncircular orifices. Both liquid/liquid and gas/liquid element types are discussed. Unlike doublet and triplet elements (circular orifices only) were investigated for the liquid/liquid case while concentric tube elements were investigated for the gas/liquid case. It is concluded that noncircular shape can be employed to significant advantage in injector design for liquid rocket engines.
    Keywords: PROPULSION SYSTEMS
    Type: R-9270 , NASA-CR-134286
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Publication Date: 2013-08-31
    Description: Rotating and positive displacement pumps of various types were studied for pumping liquid fluorine for low-thrust, high-performance rocket engines. Included in the analysis were: centrifugal, pitot, Barske, Tesla, drag, gear, vane, axial piston, radial piston, diaphragm, and helirotor pump concepts. The centrifugal pump and the gear pump were selected and these were carried through detailed design and fabrication. Mechanical difficulties were encountered with the gear pump during the preliminary tests in Freon-12. Further testing and development was therefore limited to the centrifugal pump. Tests on the centrifugal pump were conducted in Freon-12 to determine the hydrodynamic performance and in liquid fluorine to demonstrate chemical compatibility.
    Keywords: PROPULSION SYSTEMS
    Type: R-8494-1-VOL-1 , NASA-CR-72965
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Publication Date: 2013-08-31
    Description: The effect of film coolant ejection from the pressure side of a stator blade was determined in a two-dimensional cascade. Stator exit surveys were made for each of six rows of coolant holes. Successive multirow tests were made with two, three, four, five, and six rows of coolant holes open. The results of the multirow tests are compared with the predicted multirow performance obtained by adding the single-row data. Results are presented in terms of stator primary-air efficiency as a function of coolant fraction.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3045 , E-7817
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 2013-08-31
    Description: The technical feasibility is described of substantially reducing the noise levels of existing JT8D powered aircraft by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major technical problems exist that preclude the development and installation of refanned engines on aircraft currently powered by the JT8D engine. The refan concept is technically feasible and provides calculated noise reductions of from 7 to 8 EPNdb for the B727-200 aircraft and from 10 to 12 EPNdb for the DC-9-32 aircraft at the FAR Part 36 measuring stations. These noise levels are lower than both the FAR Part 36 noise standards and the noise levels of the wide-body DC-10-10. Corresponding reductions in the 90 EPNdb footprint area are estimated to vary from about 70 percent for the DC-9 to about 80 percent for the B727.
    Keywords: PROPULSION SYSTEMS
    Type: E-7942 , NASA-TM-X-71536 , Air Transport Meeting; 30 Apr. - 2 May 1974; Dallas
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Publication Date: 2013-08-31
    Description: Emissions of total oxides of nitrogen, unburned hydrocarbons, carbon monoxide, and carbon dioxide from a J-58 engine at simulated flight conditions of Mach 2.0, 2.4, and 2.8 at 19.8 km altitude are reported. For each flight condition, measurements were made for four engine power levels from maximum power without afterburning through maximum afterburning. These measurements were made 7 cm downstream of the engine primary nozzle using a single point traversing gas sample probe. Results show that emissions vary with flight speed, engine power level, and with radial position across the exhaust.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71532 , E-7935
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 2013-08-31
    Description: The test program conducted to characterize the steady state stability, thermal, and performance characteristics of the integrated thrust chamber assembly, as well as limited tests to investigate transient characteristics are described.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134256 , ASR74-117
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: The acoustic investigation and evaluation of the C propulsion turbofan engine are discussed. The engine was built as a part of the Quiet Engine Program. The objectives of the program are as follows: (1) to determine the noise levels produced turbofan bypass engines, (2) to demonstrate the technology and innovations which will reduce the production and radiation of noise in turbofan engines, and (3) to acquire experimental acoustic and aerodynamic data for high bypass turbofan engines to provide a better understanding of noise production mechanisms. The goals of the program called for a turbofan engine 15 to 20 PNdB quieter than currently available engines in the same thrust class.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-121176 , R73AEG364
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Publication Date: 2013-08-31
    Description: The effect of incidence angle on the aerodynamic performance of an uncooled core turbine rotor blade was investigated experimentally in a two-dimensional cascade. The cascade test covered a range of incidence angles from minus 15 deg to 15 deg in 5-degree increments and a range of pressure ratios corresponding to ideal exit critical velocity ratios of 0.6 to 0.95. The principal measurements were blade-surface static pressures and cross-channel surveys of exit total pressure, static pressure, and flow angle. The results of the investigation include blade-surface velocity distribution and overall performance in terms of weight flow and loss for the range of incidence angles and exit velocity ratios investigated. The measured losses are also compared with two common methods of predicting incidence loss.
    Keywords: PROPULSION SYSTEMS
    Type: E-7835 , NASA-TM-X-3047
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Publication Date: 2013-08-31
    Description: Based on FAA data, results are presented that establish (1) the incidence of rotor failure, (2) the type of fragments generated, (3) whether or not these fragments were contained, (4) the causes of failure, (5) where in the engine failure occurred, (6) what engines were affected and (7) what flight conditions prevailed at failure. The rate of uncontained rotor burst was considered to be significantly high. Blade fragments were generated in 95% of the rotor bursts, 20% of which were uncontained. Although fewer disk and rim fragment bursts occurred, none were contained.
    Keywords: PROPULSION SYSTEMS
    Type: NAPTC-PE-40 , NASA-CR-136900
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Publication Date: 2013-08-31
    Description: An axial flow compressor stage, having tandem airfoil blading, was designed for zero rotor prewhirl, constant rotor work across the span, and axial discharge flow. The stage was designed to produce a pressure ratio of 1.265 at a rotor tip velocity of 757 ft/sec. The rotor has an inlet hub/tip ratio of 0.8. The design procedure accounted for the rotor inlet boundary layer and included the effects of axial velocity ratio and secondary flow on blade row performance. The objectives of this experimental program were (1) to obtain performance with uniform and distorted inlet flow for comparison with the performance of a stage consisting of single-airfoil blading designed for the same vector diagrams and (2) to evaluate the effectiveness of accounting for the inlet boundary layer, axial velocity ratio, and secondary flows in the stage design.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134529 , FR-5955
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Publication Date: 2013-08-31
    Description: Aerodynamic and acoustic characteristics are presented for a cowlmounted, model cascade thrust reverser suitable for short-haul aircraft. Thrust reverser efficiency and the influence on fan performance were determined from isolated fan-driven models under static and forward velocity conditions. Cascade reverser noise characteristics were determined statically in an isolated pipe-flow test, while aerodynamic installation effects were determined with a wind-tunnel, fan-powered airplane model. Application of test results to short-haul aircraft calculations demonstrated that such a cascade thrust reverser may be able to meet both the performance and noise requirements for short-haul aircraft operation. However, aircraft installation effects can be quite significant.
    Keywords: PROPULSION SYSTEMS
    Type: E-8119 , NASA-TM-X-71614 , Propulsion Conf.; 21-23 Oct. 1974; San Diego, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: Criteria for the design and development of turbines for rocket engines to meet specific performance, and installation requirements are summarized. The total design problem, and design elements are identified, and the current technology pertaining to these elements is described. Recommended practices for achieving a successful design are included.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-SP-8110
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Publication Date: 2013-08-31
    Description: A finite element stress analysis was performed for the film cooled throat section of an attitude control thruster. The anlaysis employed the RETSCP finite element computer program. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the thruster operating cycle. The configuration and operating conditions considered, correspond to a flightweight integrated thruster assembly which was thrust pulse tested. The computed strain range was used in conjuction with Haynes 188 Universal Slopes minimum life data to predict throat section fatigue life. The computed number of cycles to failure was greater than the number of pulses to which the thruster was experimentally subjected without failure.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134641-VOL-2
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: A program has been conducted in order to improve the performance characteristics of 30 cm thrusters. This program was divided into three distinct, but related tasks: (1) the discharge chamber and component design modifications proposed for inclusion in the engineering model thruster were evaluated and engineering specifications were verified; (2) thrust losses which result from the contributions of double charged ions and nonaxial ion trajectories to the ion beam current were measured and (3) the specification and verification of power processor and control requirements of the engineering model thruster design were demonstrated. Proven design modifications which provide improved efficiencies are incorporated into the engineering model thruster during a structural re-design without introducing additional delay in schedule or new risks. In addition, a considerable amount of data is generated on the relation of double ion production and beam divergence to thruster parameters. Overall thruster efficiency is increased from 68% to 71% at full power, including corrections for double ion and beam divergence thrust losses.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134687
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 2013-08-31
    Description: A computer program, designated RETSCP, for the analysis of Rocket Engine Thermal Strain with Cyclic Plasticity is described. RETSCP is a finite element program which employs a three dimensional isoparametric element. The program treats elasto-plastic strain cycling including the effects of thermal and pressure loads and temperature dependent material properties. Theoretical aspects of the finite element method are discussed and the program logic is described. A RETSCP User's Manual is presented including sample case results.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134640
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: Two engineering model 30-cm ion thrusters were assembled, calibrated, and qualification tested. This paper discusses the thruster design, performance, and power system. Test results include documentation of thrust losses due to doubly charged mercury ions and beam divergence by both direct thrust measurements and beam probes. Diagnostic vibration tests have led to improved designs of the thruster backplate structure, feed system, and harness. Thruster durability is being demonstrated over a thrust range of 97 to 113 mN at a specific impulse of about 2900 seconds. As of August 15, 1974, the thruster has successfully operated for over 4000 hours.
    Keywords: PROPULSION SYSTEMS
    Type: E-8087 , NASA-TM-X-71603 , Propulsion Conf.; 21-23 Oct. 1974; San Diego, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Publication Date: 2013-08-31
    Description: An operating manual for the coaxial injection combustion model (CICM) is presented as the final report for an eleven month effort designed to provide improvement, to verify, and to document the comprehensive computer program for analyzing the performance of thrust chamber operation with gas/liquid coaxial jet injection. The effort culminated in delivery of an operation FORTRAN IV computer program and associated documentation pertaining to the combustion conditions in the space shuttle main engine. The computer program is structured for compatibility with the standardized Joint Army-Navy-NASA-Air Force (JANNAF) performance evaluation procedure. Use of the CICM in conjunction with the JANNAF procedure allows the analysis of engine systems using coaxial gas/liquid injection.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-129031
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Publication Date: 2013-08-31
    Description: Four injector designs and two chamber profiles were experimentally evaluated for structural integrity, combustion efficiency, and resistance to combustion instabilities. Vacuum thrust measurements were used as a primary measure of combustion efficiency. Stability rating to test the sensitivity of the injectors to high frequency combustion was conducted, but not extensively. To map the boundary between stable operation and chugging instability, chamber pressure was throttled downward from 689.5 to 206.9 kN/sq m abs (100 to 30 psia). Best operational results were obtained with an injector configuration having no hydraulic swirlers, a 0.00102-m (0.040-in.) recessed FLOX tube, and a nonflared exit in the methane annulus. This injector design exhibited stable combustion and good integrity of hardware, and it exceeded the design goal efficiency (88 percent) at the 10 to 1 throttled condition.
    Keywords: PROPULSION SYSTEMS
    Type: E-7911 , NASA-TM-X-3094
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 2013-08-31
    Description: The characteristics and performance of the orbit maneuvering engine for the space shuttle are discussed. Emphasis is placed on the regeneratively cooled thrust chamber of the engine. Tests were conducted to determine engine operating parameters during the start, shutdown, and restart. Characteristics of the integrated thrust chamber and the performance and thermal conditions for blowdown operation without supplementary boundary layer cooling were investigated. The results of the test program are presented.
    Keywords: PROPULSION SYSTEMS
    Type: ASR74-229 , NASA-CR-140250
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Publication Date: 2013-08-31
    Description: A 51-cm-diam. model of a short-haul fan stage was tested. Surveys of the air flow conditions ahead of the rotor, between the rotor and stator, and behind the stator were made over the stable operating range of the stage. At the design speed of 213.3 m/sec and weight flow of 26.7 kg/sec, the stage pressure ratio and efficiency are 1.18 and 0.87, respectively. The rotor peak efficiency of 0.92 occurred at flow rate of 30.5 kg/sec. Peak stage efficiency of 0.09 was obtained at 110 percent speed at a pressure ratio of 1.218 and a weight flow of 30.2 kg/sec. Maximum stage pressure ratio is 1.269 at 120 percent speed.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3101 , E-7791
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: Experimental evaluation under simulated engine conditions revealed that conventional mainshaft seals have disadvantages of high gas leakage rates and wear. An advanced seal concept, the self-acting face seal, has a much lower gas leakage rate and greater pressure and speed capability. In endurance tests (150 hr) to 43 200 rpm the self-acting seal wear was not measurable, indicating noncontact sealing operation was maintained even at this high rotative speed. A review of published data revealed that the leakage through gas path seals has a significant effect on TSFC, stall margin and engine maintenance. Reducing leakages by reducing seal clearances results in rubbing contact, and then the seal thermal response and wear determines the final seal clearances. The control of clearances requires a material with the proper combination of rub tolerance (abradability) and erosion resistance. Increased rub tolerance is usually gained at the expense of reduced erosion resistance and vice versa.
    Keywords: PROPULSION SYSTEMS
    Type: E-8096 , NASA-TM-X-71607 , Propulsion Conf.; 21-24 Oct. 1974; San Diego, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: The problem of fretting in aircraft turbine engines is discussed. Critical fretting can occur on fan, compressor, and turbine blade mountings, as well as on splines, rolling element bearing races, and secondary sealing elements of face type seals. Structural fatigue failures have been shown to occur at fretted areas on component parts. Methods used by designers to reduce the effects of fretting are given.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71606 , E-8090 , Specialists Meeting on Friction and Wear in Aircraft Systems; 11-12 Oct. 1974; Munich
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2013-08-31
    Description: A structural integrated ion thruster with 8-cm beam diameter (SIT-8) was developed for attitude control and stationkeeping of synchronous satellites. As optimized, the system demonstrates a thrust T=1.14 mlb (not corrected for beam V sub B = 1200 V (I sub sp = 2200 sec) total propellant utilization efficiency nu sub u = 59.8% (is approximately 72% without auxiliary pulse-igniter electrode), and electrical efficiency n sub E 61.9%. The thruster incorporates a wire-mesh anode and tantalum cover surfaces to control discharge chamber flake formation and employs an auxiliary pulse-igniter electrode for hollow-cathode ignition. When the SIT-8 is integrated with the compatible SIT-5 propellant tankage, the system envelope is 35 cm long by 13 cm flange bolt circle with a mass of 9.8 kg including 6.8 kg of mercury propellant. Two thrust vectoring systems which generate beam deflections in two orthogonal directions were also developed under the program and tested with the 8-cm thruster. One system vectors the beam over + or - 10 degrees by gimbaling of the entire thruster (not including tankage), while the other system vectors the beam over + or - 7 degrees by translating the accel electrode relative to the screen electrode.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134685
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Publication Date: 2013-08-31
    Description: The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.
    Keywords: PROPULSION SYSTEMS
    Type: R74AEG327 , NASA-CR-134660
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 2013-08-31
    Description: A 50-cm-diam. axial-flow transonic compressor stage with multiple-circular-arc blades was designed and tested. At design speed, a rotor peak efficiency of 0.85 occurred at an equivalent weight flow of 29.3 kg/sec. Stage peak efficiency was 0.79 at 28.6 kg/sec. Stage total pressure ratio at peak efficiency was 1.84. The stall margin at design speed was 5 percent. Rotor and stator losses were higher than predicted. The stator choked at design flow.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3100 , E-7377
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Publication Date: 2013-08-31
    Description: Flyover and static noise data from several engines are presented that show inlet fan noise measured in flight can be lower than that projected from static tests for some engines. The differences between flight and static measurements appear greatest when the fan fundamental tone due to rotor-stator interaction or to the rotor alone field is below cutoff. Data from engine and fan tests involving inlet treatment on the walls only are presented that show the attenuation from this treatment is substantially larger than expected from previous theories or flow duct experience. Data showing noise shielding effects due to the location of the engine on the airplane are also presented. These observations suggest that multiringed inlets may not be necessary to achieve the desired noise reduction in many applications.
    Keywords: PROPULSION SYSTEMS
    Type: E-8045 , NASA-TM-X-71591 , Aircraft Design Flight test and Operations Meeting; 12-14 Aug. 1974; Los Angeles
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Publication Date: 2013-08-31
    Description: A significant effort within the NASA Quiet Engine Program has been devoted to acoustical evaluation at the Lewis Research Center noise test facility of a family of full-scale fans. This report, documents the noise results obtained with fan A - a 1.5-pressure-ratio, 1160-ft/sec-tip-speed fan. The fan is described and some aerodynamic operating data are given. Far-field noise around the fan was measured for a variety of configurations pertaining to acoustical treatment and over a range of operating conditions. Complete results of 1/3-octave band analysis of the data are presented in tabular form. Included also are power spectra and sideline perceived noise levels. Some representative 1/3-octave band data are presented graphically, and sample graphs of continuous narrow-band spectra are also provided.
    Keywords: PROPULSION SYSTEMS
    Type: E-7857 , NASA-TM-X-3066
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Publication Date: 2013-08-31
    Description: The particle motion in two-dimensional free and forced inward flowing vortices is considered. A particle in such a flow field experiences a balance between the aerodynamic drag forces that tend to drive erosive particles toward the axis, and centrifugal forces that prevent these particles from traveling toward the axis. Results predict that certain sizes of particles will achieve a stable orbit about the turbine axis in the inward flowing free vortex. In this condition, the radial drag force is equal to the centrifugal force. The sizes of particles that will achieve a stable orbit is shown to be related to the gas flow velocity diagram at a particular radius. A second analysis yields a description of particle sizes that will experience a centrifugal force that is greater than the radial component of the aerodynamic drag force for a more general type of particle motion.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134616
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Publication Date: 2013-08-31
    Description: Emissions of total oxides of nitrogen, unburned hydrocarbons, and carbon monoxide from a J-58 engine at simulated flight conditions of Mach 2.0, 2.4, and 2.8 at 19.8 km altitude are reported. For each flight condition, measurements were made for four engine power levels from maximum power without afterburning through maximum afterburning. These measurements were made 7 cm downstream of the engine primary nozzle using a single point traversing gas sample probe. Results show that emissions vary with flight speed, engine power level, and with radial position across the exhaust.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71571 , E-7935 , Intern. Conf. on the Environ. Impact of Aerospace Operations; 8-10 Jul. 1974; San Diego, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Publication Date: 2013-08-31
    Description: A miniature solid propellant rocket motor has been developed to be used in a program to determine those parameters which must be duplicated in a cold gas flow to produce aerodynamic effects on an experimental model similar to those produced by hot, particle-laden exhaust plumes. Phenomena encountered during the testing of the miniature solid propellant motors included erosive propellant burning caused by high flow velocities parallel to the propellant surface, regressive propellant burning as a result of exposed propellant edges, the deposition of aluminum oxide on the nozzle surfaces sufficient to cause aerodynamic nozzle throat geometry changes, and thermal erosion of the nozzle throat at high chamber pressures. A series of tests was conducted to establish the stability of the rocket chamber pressure and the repeatibility of test conditions. Data are presented which define the tests selected to represent the final test matrix. Qualitative observations are also presented concerning the phenomena experienced based on the results of a large number or rocket tests not directly applicable to the final test matrix.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-120276 , CALSPAN-AA-4018-W-10
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 2013-08-31
    Description: Several plasma-sprayed coating systems were evaluated for structural stability in hydrogen plasma and in oxygen plasma mixed with hydrogen plasma. The principal test heat flux was 15 Btu per inch squared seconds. The system consisted of a number of thin 0.002 to 0.020 in. layers of metal oxides and/or metals. The principal materials included are molybdenum nichrome, alumina, and zirconia. The study identifies important factors in coating system fabrication and describes the durability of the coating systems in the test environments. Values of effective thermal conductivity for some of the systems are indicated.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3072 , E-7877
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 2013-08-31
    Description: A computer program was developed to describe the performance of ramjet and scramjet cycles. The program performs one dimensional calculations of the equilibrium, real-gas internal flow properties of the engine. The program can be used for the following: (1) preliminary design calculation and (2) design analysis of internal flow properties corresponding to stipulated flow areas. Only the combustion of hydrogen in air is considered in this case.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-132454 , AP-1001-1
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Publication Date: 2013-08-31
    Description: The overall and blade-element performances and the aerodynamic design parameters of a transonic rotor with an aspect ratio of 6.5, designed to investigate the effects of aspect ratio on range and performance are presented. The rotor was designed for a total-pressure ratio of 1.53, an efficiency of 0.898, and a weight flow of 67.76 pounds per second.
    Keywords: PROPULSION SYSTEMS
    Type: E-7641 , NASA-TN-D-7662
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    facet.materialart.
    facet.materialart.
    In:  CASI
    Publication Date: 2016-03-07
    Description: A study was conducted to determine the promising propulsion systems for advanced supersonic transport application, and to identify the critical propulsion technology requirements. It is shown that noise constraints have a major effect on the selection of the various engine types and cycle parameters. Several promising advanced propulsion systems were identified which show the potential of achieving lower levels of sideline jet noise than the first generation supersonic transport systems. The non-afterburning turbojet engine, utilizing a very high level of jet suppression, shows the potential to achieve FAR 36 noise level. The duct-heating turbofan with a low level of jet suppression is the most attractive engine for noise levels from FAR 36 to FAR 36 minus 5 EPNdb, and some series/parallel variable cycle engines show the potential of achieving noise levels down to FAR 36 minus 10 EPNdb with moderate additional penalty. The study also shows that an advanced supersonic commercial transport would benefit appreciably from advanced propulsion technology. The critical propulsion technology needed for a viable supersonic propulsion system, and the required specific propulsion technology programs are outlined.
    Keywords: PROPULSION SYSTEMS
    Type: PWA-TM-4871 , NASA-CR-134633
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Publication Date: 2013-08-31
    Description: Arcs representative of those occurring between the grids of a mercury ion thruster were simulated. Parameters affecting an arc and the resulting damage were studied. The parameters investigated were arc energy, arc duration, and grid geometry. Arc attenuation techniques were also investigated. Potentially serious damage occurred at all energy levels representative of actual thruster operating conditions. Of the grids tested, the lowest open-area configuration sustained the least damage for given conditions. At a fixed energy level a long duration discharge caused greater damage than a short discharge. Attenuation of arc current using various impedances proved to be effective in reducing arc damage. Faults were also deliberately caused using chips of sputtered materials formed during the operation of an actual thruster. These faults were cleared with no serious grid damage resulting using the principles and methods developed in this study.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3044 , E-7767
    Format: application/pdf
    Location Call Number Expected Availability