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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 379 records · Page 21

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NASA NTRS1976

Space shuttle L-tube radiator testing

A series of tests were conducted to support the development of the Orbiter Heat Rejection System. The details of the baseline radiator were defined by designing, fabricating, and testing representative hardware. The tests were performed in the Space Environmental Simulation Laboratory Chamber A. An IR source was used to simulate total solar and infrared environmental loads on the flowing shuttle radiators panel. The thermal and mechanical performance of L tube space radiators and their thermal coating were established.

Phillips, M. A.↗

NASA NTRS1978

Properties of aspect-ratio-4.0 rectangular jets in a subsonic crossflow

A series of wind-tunnel and laboratory tests were conducted at the NASA Langley V/STOL tunnel facility to determine both the detailed structure and the induced effects of aspect-ratio-4.0 rectangular jets both in a subsonic crosswind and in quiescent conditions. Wind-tunnel tests were conducted on both blunt (nozzle major axis normal to free stream) and streamwise (nozzle major axis parallel to free stream) nozzle orientations for jet injection angles ranging from 15 to 90 degrees at jet-to-crossflow velocity ratios of 4, 8, and 10. Results indicate that the blunt nozzle induced effects are more significant than those produced by comparable streamwise-oriented jets and that both the flow-field structure and induced effects of streamwise-oriented rectangular jets are quite similar to those created by round jets. Additionally, it is shown that significant differences exist in the vortex flow fields generated by the same rectangular nozzle mounted in two different test hardware configurations.

Thames, F. C.↗

NASA NTRS1978

Definition study of a Variable Cycle Experimental Engine (VCEE) and associated test program and test plan

The Definition Study of a Variable Cycle Experimental Engine (VCEE) and Associated Test Program and Test Plan, was initiated to identify the most cost effective program for a follow-on to the AST Test Bed Program. The VCEE Study defined various subscale VCE's based on different available core engine components, and a full scale VCEE utilizing current technology. The cycles were selected, preliminary design accomplished and program plans and engineering costs developed for several program options. In addition to the VCEE program plans and options, a limited effort was applied to identifying programs that could logically be accomplished on the AST Test Bed Program VCE to extend the usefulness of this test hardware. Component programs were provided that could be accomplished prior to the start of a VCEE program.

Allan, R. D.↗

NASA NTRS1978

Space Shuttle Program description and status

The main reason for the development of the Space Shuttle is related to the aim to achieve a major reduction in the cost of placing a payload into space. Such a reduction is to be obtained by using a reusable in place of an expendable launch vehicle. Developments concerning launch vehicles show a steady reduction in launching expenses. From a cost of about $500,000 a pound in the late 1950's, launching expenses were reduced to $600 a pound for payloads on the Saturn V. With the Space Shuttle the cost will drop to approximately $150 a pound. The Space Shuttle Program is discussed, taking into account a system description, a typical mission profile, aspects of mission design, launch costs, and Space Shuttle characteristics. The Space Shuttle Program status is also examined, giving attention to orbital flight schedules, flight hardware tests, launch area facilities, the mission control center, and details of flight crew training.

Macleod, J. B.↗

NASA NTRS1979

Investigation of high frequency oscillations in the OV102 elevon actuation subsystems using continuous system modeling program simulation

Two theories emerged as the cause of undesired oscillations at frequencies between 40 and 60 Hz in the Orbiter Vehicle inboard and outboard elevon actuation subsystems during hardware testing. Both the "hardover feedback" and "deadspace" theories were examined using continuous system modeling program simulation. Results did not support the "hardover feedback" theory but showed that deadspace in the torque feedback spring connections to the servospools must be considered to be a possible cause of the oscillations. Further investigation is recommended.

Powell, W. W., Sr.↗

NASA NTRS1979

Manufacturing processes for fabricating graphite/PMR 15 polyimide structural elements

Investigations were conducted to obtain commercially available graphite/PMR-15 polyimide prepreg, develop an autoclave manufacturing process, and demonstrate the process by manufacturing structural elements. Controls were established on polymer, prepreg, composite fabrication, and quality assurance, Successful material quality control and processes were demonstrated by fabricating major structural elements including flat laminates, hat sections, I beam sections, honeycomb sandwich structures, and molded graphite reinforced fittings. Successful fabrication of structural elements and simulated section of the space shuttle aft body flap shows that the graphite/PMR-15 polyimide system and the developed processes are ready for further evaluation in flight test hardware.

Sheppard, C. H.↗

NASA NTRS1980

Proceedings of the First Semiannual Distributed Receiver Program Review

Point focus and line focus distributed receiver solar thermal technology for the production of electric power and of industrial process heat is addressed. Concentrator, receiver, and power conversion development are covered along with hardware tests and evaluation. Mass production costing, parabolic dish applications, and trough and bowl systems are included.

Source record↗

NASA NTRS1979

Development of the electrochemically regenerable carbon dioxide absorber for portable life support system application

As the length of manned space missions increase, more ambitious extravehicular activities (EVAs) are required. For the projected longer mission the use of expendables in the portable life support system (PLSS) will become prohibited due to high launch weight and volume requirements. Therefore, the development of a regenerable CO2 absorber for the PLSS application is highly desirable. The paper discusses the concept, regeneration mechanism, performance, system design, and absorption/regeneration cycle testing of a most promising concept known as ERCA (Electrochemically Regenerable CO2 Absorber). This concept is based on absorbing CO2 into an alkaline absorbent similar to LiOH. The absorbent is an aqueous solution supported in a porous matrix which can be electrochemically regenerated on board the primary space vehicle. With the metabolic CO2 recovery the ERCA concept results in a totally regenerable CO2 scrubber. The ERCA test hardware has passed 200 absorption/regeneration cycles without performance degradation.

Woods, R. R.↗

NASA NTRS1981

The JPL isolated application experiment series

The technical, operational, and economic readiness of parabolic dish power systems for a variety of applications in the power range below 10 MWe are discussed. Power systems are developed and tested to the point where commercialization efforts lead to successful market penetration. A key element in this strategy is the use of experiments to test hardware and assess operational readiness. The Isolated Application Experiments are described and their objectives discussed.

Levin, R. R.↗

NASA NTRS1982

Application of integration algorithms in a parallel processing environment for the simulation of jet engines

The application of Predictor corrector integration algorithms developed for the digital parallel processing environment are investigated. The algorithms are implemented and evaluated through the use of a software simulator which provides an approximate representation of the parallel processing hardware. Test cases which focus on the use of the algorithms are presented and a specific application using a linear model of a turbofan engine is considered. Results are presented showing the effects of integration step size and the number of processors on simulation accuracy. Real time performance, interprocessor communication, and algorithm startup are also discussed.

Krosel, S. M.↗

NASA NTRS1981

Development of a simple, self-contained flight test data acquisition system

A low cost flight test data acquisition system, applicable to general aviation airplanes, was developed which meets criteria for doing longitudinal and lateral stability analysis. Th package consists of (1) a microprocessor controller and data acquisition module; (2) a transducer module; and (3) a power supply module. The system is easy to install and occupies space in the cabin or baggage compartment of the airplane. All transducers are contained in these modules except the total pressure tube, static pressure air temperature transducer, and control position transducers. The NASA-developed MMLE program was placed on a microcomputer on which all data reduction is done. The flight testing program undertaken proved both the flight testing hardware and the data reduction method to be applicable to the current field of general aviation airplanes.

Renz, R. R. L.↗

NASA NTRS1982

The P-POD Project

The programmable pilot oriented display (P-POD), a multiprocessor based flight information processing and display unit, is discussed. Communication protocols between the three Z-80 processors inside P-POD are reviewed. The interface between the video processor, P2, and the main processor, P1, was tested. Hardware and software were revised. Data flow between P1 and P2 is illustrated. While running diagnostic routines to exercise the P1/P2 interface at maximum speed an intermittent failure was observed. A check of possible noise sources or race conditions in the hardware did not reveal the source of this failure. Possible software timing problems were also fully investigated. To eliminate the effects of this type of failure a performance monitor routine was used to detect these occasional failures and correct them. The data transmission cycle between P1/P2 is either allowed to continue normal operation or is re-initialized and restarted when an error is detected.

Littlefield, J. A.↗

NASA NTRS1982

High-pressure LOX/hydrocarbon preburner injector investigation

The NASA-MSFC program to furnish a high-pressure LOX/hydrocarbon turbine drive combustor technology base for future booster engine programs is discussed. The program evaluated the LOX/RP-1 and LOX/methane preburner and gas generator performance and gas property prediction methods for fuel-rich and oxidizer-rich operating conditions. A small-scale hardware test program, which included 42 hot-fire tests of fuel-rich LOX/methane and LOX/RP-1 and oxidizer-rich LOX/methane, supplied information to reduce uncertainties in prediction techniques. The hot-fire results show that theoretical computer model features should be modified to support curves generated from experimental data.

Huebner, A. W.↗

NASA NTRS1983

Implementation of R & QA practices in Research and Development programs

DOE has established a number of broad programs aimed at reducing fuel consumption. Several programs address the R&D of ground transportation propulsion alternatives to the conventional spark-ignition engine. NASA Lewis is responsible for managing the effort between the Government and industry teams involving American and foreign companies. Thus, existing NASA SR&QA procedure were modified/adapted to these R&D programs and implemented to assure that the test hardware design intent was met, the hardware was not hazardous to personnel, it would demonstrate reliable operation, and it would help establish the future R&D quality assurance and maintainability requirements. This successful low-cost approach might be applicable to other similar projects.

Bankaitis, H.↗

NASA NTRS1983

Noise characterization and minimization of a precision gyroscopic rate sensor

A program has been conducted to evaluate the noise signature of Space Telescope gyros. The Space Telescope gyros provide a three-axis attitude reference using six single-degree-of-freedom gyroscopes operated with pulse rebalance electronics; the rate sensor attitude quantization is 0.00025 arcsec. The results of the noise evaluation program, including error source characterization and identification of candidate design modifications, are summarized together with the results of prototype hardware testing. It is shown that the proposed design modifications can significantly improve the rate sensor noise performance.

Dougherty, H.↗

NASA NTRS1984

Ground correlation investigation of thruster spacecraft interactions to be measured on the IAPS flight test

Preliminary ground correlation testing has been conducted with an 8 cm mercury ion thruster and diagnostic instrumentation replicating to a large extent the IAPS flight test hardware, configuration, and electrical grounding/isolation. Thruster efflux deposition retained at 25 C was measured and characterized. Thruster ion efflux was characterized with retarding potential analyzers. Thruster-generated plasma currents, the spacecraft common (SCC) potential, and ambient plasma properties were evaluated with a spacecraft potential probe (SPP). All the measured thruster/spacecraft interactions or their IAPS measurements depend critically on the SCC potential, which can be controlled by a neutralizer ground switch and by the SPP operation.

Power, J. L.↗

NASA NTRS1985

Space Shuttle Orbiter waste collection system conceptual study

The analyses and studies conducted to develop a recommended design concept for a new fecal collection system that can be retrofited into the space shuttle vehicle to replace the existing troublesome system which has had limited success in use are summarized. The concept selected is a cartridge compactor fecal collection subsystem which utilizes an airflow collection mode combined with a mechanical compaction and vacuum drying mode that satisfies the shuttle requirements with respect to size, weight, interfaces, and crew comments. A follow-on development program is recommended which is to result in flight test hardware retrofitable on a shuttle vehicle. This permits NASA to evaluate the system which has space station applicablity before committing production funds for the shuttle fleet and space station development.

Abbate, M.↗

NASA NTRS1984

Ground correlation investigation of thruster/spacecraft interactions to be measured on the IAPS flight test

Power, J. L.↗