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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Auxiliary propulsion requirements for large space systems

An insight into auxiliary propulsion systems (APS) requirements for large space systems (LSS) launchable by a single shuttle is presented. In an effort to scope the APS requirements for LSS, a set of generic LSSs were defined. For each generic LSS class a specific structural configuration, representative of that most likely to serve the needs of the 1980's and 1990's was defined. The environmental disturbance forces and torques which would be acting on each specific structural configuration in LEO and GEO orbits were then determined. Auxiliary propulsion requirements were determined as a function of: generic class specific configuration, size and openness of structure, orbit, angle of orientation, correction frequency, duty cycle, number and location of thrusters and direction of thrusters and APS/LSS interactions. The results of this analysis were used to define the APS characteristics of: (1) number and distribution of thrusters, (2) thruster modulation, (3) thrust level, (4) mission energy requirements, (5) total APS mass component breakdown, and (6) state of the art adequacy/deficiency.

Maloy, J. E.↗
NASA NTRS1982

Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors

A model supersonic inlet with auxiliary inlet doors and bounday layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9x15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression.

Woodward, R. P.↗
NASA NTRS1983

Auxiliary propulsion requirements for large space systems

An insight into auxiliary propulsion systems (APS) requirements for large space systems (LSS) launchable by a single shuttle is presented. In an effort to scope the APS requirements for LSS, a set of generic LSSs were defined. For each generic LSS class a specific structural configuration, representative of that most likely to serve the needs of the 1980's and 1990's was defined. The environmental disturbance forces and torques which would be acting on each specific structural configuration in LEO and GEO orbits were then determined. Auxiliary propulsion requirements were determined as a function of: generic class specific configuration, size and openness of structure, orbit, angle of orientation, correction frequency, duty cycle, number and location of thrusters and direction of thrusters and APS/LSS interactions. The results of this analysis were used to define the APS characteristics of: (1) number and distribution of thrusters, (2) thruster modulation, (3) thrust level, (4) mission energy requirements, (5) total APS mass component breakdown, and (6) state of the art adequacy/deficiency. Previously announced in STAR as N83-26922

Maloy, J. E.↗
NASA NTRS1983

Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors

A model supersonic inlet with auxiliary inlet doors and boundary layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9 x 15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression. Previously announced in STAR as N83-27794

Woodward, R. P.↗
NASA NTRS1983

Study of auxiliary propulsion requirements for large space systems. Volume 1: Executive summary

An insight into auxiliary propulsion systems (APS) requirements for large space systems (LSS) launchable by a single shuttle is presented. In an effort to scope the APS requirements for LSS, a set of generic LSSs were defined. For each generic LSS class a specific structural configuration, representative of that most likely to serve the needs of the 1980's and 1990's was defined. The environmental disturbance forces and torques which would be acting on each specific structural configuration in LEO and GEO orbits were then determined. Auxiliary propulsion requirements were determined as a function of: generic class specific configuration, size and openness of structure, orbit, angle of orientation, correction frequency, duty cycle, number and location of thrusters and direction of thrusters and APS/LSS interactions. The results of this analysis were used to define the APS characteristics of: (1) number and distribution of thrusters, (2) thruster modulation, (3) thrust level, (4) mission energy requirements, (5) total APS mass component breakdown, and (6) state of the art adequacy/deficiency.

Smith, W. W.↗
NASA NTRS1984

Space Shuttle Orbiter improved auxiliary power unit

The Space Shuttle Orbiter Auxiliary Power Unit subsystem has operated successfully on three vehicles by meeting mission requirements and has proven the design for space operation. The current Auxiliary Power Unit (APU) operational life is limited to 12 missions and the APU turnaround between flights is longer than originally anticipated. The Improved APU objective is to increase life to 50 missions, reduce the three - APU subsystem vehicle weight by 140 lbs., and reduce turnaround time. The design changes incorporated into the Improved APU and the associated development testing are described.

Hagemann, D. W.↗
NASA NTRS1988

Component Data Base for Space Station Resistojet Auxiliary Propulsion

The resistojet was baselined for Space Station auxiliary propulsion because of its operational versatility, efficiency, and durability. This report was conceived as a guide to designers and planners of the Space Station auxiliary propulsion system. It is directed to the low thrust resistojet concept, though it should have application to other station concepts or systems such as the Environmental Control and Life Support System (ECLSS), Manufacturing and Technology Laboratory (MTL), and the Waste Fluid Management System (WFMS). The information will likely be quite useful in the same capacity for other non-Space Station systems including satellite, freeflyers, explorers, and maneuvering vehicles. The report is a catalog of the most useful information for the most significant feed system components and is organized for the greatest convenience of the user.

Bader, Clayton H.↗
NASA NTRS1987

Modeling and stability analysis for the upper atmosphere research satellite auxiliary array switch component

A feedback control system, called an auxiliary array switch, was designed to connect or disconnect auxiliary solar panel segments from a spacecraft electrical bus to meet fluctuating demand for power. A simulation of the control system was used to carry out a number of design and analysis tasks that could not economically be performed with a breadboard of the hardware. These tasks included: (1) the diagnosis of a stability problem, (2) identification of parameters to which the performance of the control system was particularly sensitive, (3) verification that the response of the control system to anticipated fluctuations in the electrical load of the spacecraft was satisfactory, and (4) specification of limitations on the frequency and amplitude of the load fluctuations.

Wolfgang, R.↗
NASA NTRS1988

Preliminary design study of hydrogen and ammonia resistojets for prime and auxiliary thrusters

Designs of high performance resistojets for primary and auxiliary propulsion are described.Thruster power for the primary propulsion application was in the 2 to 3 kW range while auxiliary propulsion power per thruster was 0.15 to 0.25 kW. Propellants considered were hydrogen and ammonia. The report described design techniques used to forecast the temperature and energy flux distributions using mathematical modeling by personal microcomputer. BASIC language is used throughout to give the designer rapid interaction and control. Both designs integrate compact first stage coils with concentric tubular heaters. The hybrid heater design allows better thruster power matching with the spacecraft power bus. Projected specific impulse levels were 760 to 830 s for hydrogen and 380 to 410 s for ammonia.

Page, Russell J.↗
NASA NTRS1988

A test for spatial clustering in the presence of auxiliary information

A technique is proposed to test for the presence of clusters when both spatial and auxiliary information is available. The test is based on randomizing the auxiliary information over the spatial locations. It requires no model assumptions (such as a Poisson process) for the spatial distribution. The procedure may be used to screen data for possible clustering.

Banfield, Jeff↗
NASA NTRS1956

Investigation at supersonic and subsonic Mach numbers of auxiliary inlets supplying secondary air flow to ejector exhaust nozzles

The results indicated increases in auxiliary-inlet pressure recovery with increases in scoop height relative to the boundary-layer thickness. The pressure recovery increased at about the same rate as theoretically predicted for an inlet in a boundary layer having a one-seventh power profile, but was only about 0.68 to 0.75 of the theoretically obtainable values. Under some operating conditions, flow from the primary jet was exhausted through the auxiliary inlet. This phenomenon could be predicted from the ejector pumping characteristics.

Hearth, Donald P↗
NASA NTRS1955

Preliminary Investigation of a Conical Spike Inlet in Combination with a Vertical-wedge Auxiliary Inlet at Mach Number 1.9

Pressure-recovery characteristics of a nacelle-type-spike inlet in combination with a vertical-wedge auxiliary scoop are presented for a free-stream Mach number of 1.9 at zero angle of attack. The auxiliary scoop provided 17 percent additional air flow with a drop in critical pressure recovery from 0.86 to 0.81. However, in terms of inlet-engine matching, the pressure recovery of the undersized spike inlet operating at a specified corrected air flow increased with the scoop open, for example, from 0.69 to 0.81.

Beke, Andrew↗
NASA NTRS1934

Wind-tunnel tests on combinations of a wing with fixed auxiliary airfoils having various chords and profiles

This report presents the results of wind tunnel tests on various auxiliary airfoils having three different airfoil sections and several different chord lengths in combination with a Clark y model wing in a sufficient number of relative positions to determine the optimum with regard to certain criterions of aerodynamic performance. The airfoil sections included a symmetrical profile, one of medium camber, and a highly cambered one. The chord sizes of the auxiliary airfoils ranged from 7.5 to 25 percent of the chord of the main wing, and the span was equal to that of the main wing.

Weick, Fred E↗
NASA NTRS1958

X-15 auxiliary power units and reaction controls

Electrical and hydraulic power within the X-15 airplane is developed by a monopropellant auxiliary power unit. In addition, airplane altitude control at extreme altitude is by monopropellant rockets. Two duplicate installations are used to provide reliability beyond single-system capabilities to assure continuous availability of aerodynamic flight controls and space-altitude controls. All components have been developed and evaluation tested by the individual suppliers. The principal item, the auxiliary power unit, has completed a 150 hour endurance test comprising 300 typical mission duty cycles. (author)

Wagner, Bruce O↗
NASA NTRS1992

Synchronous dynamics of a coupled shaft/bearing/housing system with auxiliary support from a clearance bearing: Analysis and experiment

This study examines the response of a flexible rotor supported by load sharing between linear bearings and an auxiliary clearance bearing. The objective of the work is to develop a better understanding of the dynamical behavior of a magnetic bearing supported rotor system interacting with auxiliary bearings during a critical operating condition. Of particular interest is the effect of coupling between the bearing/housing and shaft vibration on the rotordynamical responses. A simulation model is developed and a number of studies are performed for various parametric configurations. An experimental investigation is also conducted to compare and verify the rotordynamic behavior predicted by the simulation studies. A strategy for reducing synchronous shaft vibration through appropriate design of coupled shaft/bearing/housing vibration modes is identified. The results are presented and discussed.

Lawen, James, Jr.↗
NASA NTRS1995

Probabilistic risk assessment of the Space Shuttle. Phase 3: A study of the potential of losing the vehicle during nominal operation. Volume 5: Auxiliary shuttle risk analyses

Volume 5 is Appendix C, Auxiliary Shuttle Risk Analyses, and contains the following reports: Probabilistic Risk Assessment of Space Shuttle Phase 1 - Space Shuttle Catastrophic Failure Frequency Final Report; Risk Analysis Applied to the Space Shuttle Main Engine - Demonstration Project for the Main Combustion Chamber Risk Assessment; An Investigation of the Risk Implications of Space Shuttle Solid Rocket Booster Chamber Pressure Excursions; Safety of the Thermal Protection System of the Space Shuttle Orbiter - Quantitative Analysis and Organizational Factors; Space Shuttle Main Propulsion Pressurization System Probabilistic Risk Assessment, Final Report; and Space Shuttle Probabilistic Risk Assessment Proof-of-Concept Study - Auxiliary Power Unit and Hydraulic Power Unit Analysis Report.

Fragola, Joseph R.↗
NASA NTRS1995

Steady-state dynamic behavior of an auxiliary bearing supported rotor system

This paper investigates the steady-state responses of a rotor system supported by auxiliary bearings in which there is a clearance between the rotor and the inner race of the bearing. A simulation model based upon the rotor of a production jet engine is developed and its steady-state behavior is explored over a wide range of operating conditions for various parametric configurations. Specifically, the influence of rotor imbalance, support stiffness, and damping is studied. It is found that imbalance may change the rotor responses dramatically in terms of frequency contents at certain operating speeds. Subharmonic responses of 2nd order through 10th order are all observed except the 9th order. Chaotic phenomenon is also observed. Jump phenomena (or double-valued responses) of both hard-spring type and soft-spring type are shown to occur at low operating speeds for systems with low auxiliary bearing damping or large clearance even with relatively small imbalance. The effect of friction between the shaft and the inner race of the bearing is also discussed.

Xie, Huajun↗
NASA NTRS1995

Synchronous dynamics of a coupled shaft/bearing/housing system with auxiliary support from a clearance bearing: Analysis and experiment

This study examines the response of a flexible rotor supported by load sharing between linear bearings and an auxiliary clearance bearing. The objective is to develop a better understanding of the dynamical behavior of a magnetic bearing supported rotor system interacting with auxiliary bearings during a critical operating condition. Of particular interest is the effect of coupling between the bearing/housing and shaft vibration on the rotordynamical responses. A simulation model is developed and a number of studies are performed for various parametric configurations. An experimental investigation is also conducted to compare and verify the rotordynamic behavior predicted by the simulation studies. A strategy for reducing synchronous shaft vibration through appropriate design of coupled shaft/bearing/housing vibration modes is identified.

Lawen, James L., Jr.↗