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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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Continuously measure and record deflection of facility during testing. Facility deflections are then subtracted from shroud deflections during data reduction on computer. System is based on tracking light beam by using two-axis photo detector and feeding signals into X and Y servo system.
The convective heat transfer distribution for space shuttle configurations is discussed. The viscous/inviscid interactions associated with the complex three dimensional flow fields are examined. Two basic conditions are considered as follows: (1) models consisting of basic elemental combinations and (2) models of specific flight vehicles. The test facilities and test programs used to obtain data on the fuselage flow field and the wing flow field are described.
This paper describes the NASA portion of a joint FAA-NASA General Aviation Crashworthiness Program leading to the development of improved crashworthiness design technology. The objectives of the program are to develop analytical technology for predicting crashworthiness of structures, provide design improvements, and perform full-scale crash tests. The analytical techniques which are being developed both in-house and under contract are described, and typical results from these analytical programs are shown. In addition, the full-scale testing facility and test program are discussed.
A program was successfully completed to analytically and experimentally evaluate the feasibility of using an electrochemical oxygen (O2) concentrator as an O2 compressor. The electrochemical O2 compressor (EOC) compresses 345 kN/sq m (50 psia) O2 generated on board the space vehicle by the water electrolysis subsystem (WES) in a single stage to 20,700 kN/sq m (3000 psia) to refill spent extravehicular equipment O2 bottles and to eliminate the need for high pressure O2 storage. The single cell EOC designed, fabricated, and used for the feasibility testing is capable of being tested at O2 pressures up to 41,400 kN/sq m (6000 psia). A ground support test facility to test the EOC cell was designed, fabricated, and used for the EOC feasibility testing. A product assurance program was established, implemented, and maintained which emphasized safety and materials compatibility associated with high pressure O2 operation. A membrane development program was conducted to develop a membrane for EOC application. Data obtained using a commercially available membrane were used to guide the development of the membranes fabricated specifically for an EOC. A total of 15 membranes were fabricated.
The Multi-KW DC Distribution System Technology Research Study is the third phase of the NASA/MSFC study program. The purpose of this contract was to complete the design of the integrated technology test facility, provide test planning, support test operations and evaluate test results. The subjet of this study is a continuation of this contract. The purpose of this continuation is to study and analyze high voltage system safety, to determine optimum voltage levels versus power, to identify power distribution system components which require development for higher voltage systems and finally to determine what modifications must be made to the Power Distribution System Simulator (PDSS) to demonstrate 300 Vdc distribution capability.
The goal of a FIREMEN funded contract is the definition of a laboratory test method ranking airplane interior materials by probable performance in post-crash and in-flight fires. A major task is the relation of laboratory results to full scale data. A large test facility for testing materials to the thermal threat of fuel fed and interior fires was developed with quartz lamps and a propane burner in a twenty foot fuselage section. A method was developed to analyze full scale data for the apparent heat, smoke and toxicant release rates of the material tested.
The papers presented in this conference provided an international dialogue and a meaningful exchange in the simulation of space environments as well as the evolution of these technological advances into other fields. The papers represent a significant contribution to the understanding of space simulation problems and the utilization of this knowledge. The topics of the papers include; spacecraft testing; facilities and test equipment; system and subsystem test; life sciences, medicine and space; physical environmental factors; chemical environmental factors; contamination; space physics; and thermal protection.
The verification philosophy for the Space Telescope (ST) has evolved from years of experience with multispacecraft programs modified by the new factors introduced by the Space Transportation System. At the systems level of test, the ST will undergo joint qualification/acceptance tests with environment simulation using Lockheed's large spacecraft test facilities. These tests continue the process of detecting workmanship defects and module interface incompatibilities. The test program culminates in an 'all up' ST environmental test verification program resulting in a 'ready to launch' ST.
A design and ground test program was conducted to study the performance of the monofilar absorber for vibration reduction on a four-bladed helicopter. A monofilar is a centrifugal tuned two degree-of-freedom rotor hub absorber that provides force attenuation at two frequencies using the same dynamic mass. Linear and non-linear analyses of the coupled monofilar/airframe system were developed to study tuning and attenuation characteristics. Based on the analysis, a design was fabricated and impact bench tests verified the calculated non-rotating natural frequencies and mode shapes. Performance characteristics were measured using a rotating absorber test facility. These tests showed significant attenuation of fixed-system 4P hub motions due to 3P inplane rotating-system hub forces. In addition, detuning effects of the 3P monofilar modal response were small due to the nonlinearities and tuning pin slippage. However, attenuation of 4P hub motions due to 5P inplane hub forces was poor. The performance of the 5P monofilar modal response was degraded by torsional motion of the dynamic mass relative to the support arm which resulted in binding of the dynamic components. Analytical design studies were performed to evaluate this torsional motion problem. An alternative design is proposed which may alleviate the torsional motion of the dynamic mass.
A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is explored. An energy-absorbing test seat was designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions, was conducted at a sled test facility. Comparative tests with operational F-111 crewseats were also conducted. After successful dynamic testing of the seat, more testing was conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests were conducted. The vertical drop tests were used to obtain comparative data between the energy-absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series.
Over the past years, several papers and reports have documented the unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft. This report documents a program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats. An energy absorbing test seat was designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions, was conducted at a sled test facility. Comparative tests with operational F-111 crewseats were also conducted. After successful dynamic testing of the seat, more testing was conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests werre conducted. The vertical drop tests were used to obtain comparative data between the energy absorbing and operational seats.
The unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft is reviewed. A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is presented. An energy absorbing test seat is designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions is conducted at a sled test facility. Comparative tests with operational F-111 crewseats are also conducted. After successful dynamic testing of the seat, more testing is conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests are conducted. The vertical drop tests are used to obtain comparative data between the energy absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series. Volume 2 presents the data obtained during the seat test series, while Volume 3 presents the data from the crew module test series.
The problem of the mixing enhancement of heated jets through acoustic excitation is addressed using a 5.08 cm diameter jet operating at Mach numbers as high as 1.12 and at temperatures reaching 670 K. An experimental investigation is carried out to determine why high-speed heated jets are not as responsive to internal excitation as low-speed heated jets. Results are also presented which are related to the flow structure in the presence of screech and under the influence of external excitation. It is shown that, if sufficiently high excitation levels are used, the heated jets, even at high levels, can be modified by artificial excitation. Nonetheless, it is concluded that, for the test facility and test conditions used in the present study, the high-Mach-number heated jets are considerably less excitable than the similarly heated low-Mach-number jets.
The NASA Lewis Research Center has tested a 1 kW free-piston Stirling engine at the NASA Lewis test facilities. The tests performed over the past several years on the RE-1000 single cylinder engine are known as the sensitivity tests. This report presents an analysis of some of the data published in the sensitivity test report. A basic investigation into the measured forces acting on the unconstrained displacer of the engine is presented. These measured forces are then correlated with the values predicted by the NASA Lewis Stirling engine computer simulation. The results of the investigation are presented in the form of phasor diagrams. Possible future work resulting from this investigation is outlined.
Control Dynamics Company (CDy), in conjunction with NASA Marshall Space Flight Center (MSFC), has supported the U.S. Air Force Wright Aeronautical Laboratory (AFWAL) in conducting an investigation of the implementation of several DOD controls techniques. These techniques are to provide vibration suppression and precise attitude control for flexible space structures. AFWAL issued a contract to Control Dynamics to perform this work under the Active Control Technique Evaluation for Spacecraft (ACES) Program. The High Authority Control/Low Authority Control (HAC/LAC) and Positivity controls techniques, which were cultivated under the DARPA Active Control of Space Structures (ACOSS) Program, were applied to a structural model of the NASA/MSFC Ground Test Facility ACES configuration. The control systems design were accomplished and linear post-analyses of the closed-loop systems are provided. The control system designs take into account effects of sampling and delay in the control computer. Nonlinear simulation runs were used to verify the control system designs and implementations in the facility control computers. Finally, test results are given to verify operations of the control systems in the test facility.
The topics are presented in viewgraph form and include the following: the Electric Propulsion Research Building (no. 16) the Electric Power Laboratory (BLDG. 301); the Tank 6 Vacuum Facility; and test facilities for electric propulsion and LeRC.
An experimental investigation of multiaxis thrust vectoring nozzles with spherical convergent flaps (SCF) and a convertible (in-flight deployable) centerline plug were tested in the NASA-Langley 16-Foot Transonic Tunnel Static Test Facility. Parameters tested during the static test included plug length, external shroud length, shroud internal angle, and yaw vector angle. Results indicated that the SCF convertible-plug nozzle flow is highly three dimensional and characterized by internal flow separation and shock effects. The resultant thrust and discharge coefficient levels were lower than previous wedge nozzle results. In addition, increasing shroud internal angle increased resultant thrust ratio but decreased discharge coefficient. Increasing shroud length increased resultant thrust ratio performance for NPR's greater than 6.0 but for NPR's less than 6.0, resultant thrust ratio decreased as shroud length increased. Increasing plug length caused an increase in resultant thrust ratio and an increase in discharge coefficient. Increasing geometric yaw vector angle had no effect on resultant thrust ratio and little effect on discharge coefficient.
NASA Landing Systems Research Aircraft (LSRA) is Convair 990 airplane modified to incorporate tire-and-landing-gear test facility containing test fixture. Airplane instrumented to measure loads, velocities, and slip angles between tires and runways.