Panel discussion: Bridging the gap technology developing flight hardware
The development of an engineering data base for aerospace batteries is discussed.
Ford, F. E.↗
SEARCH · Engineering Papers
Results for “data engineering”
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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Mechanism associated with the Space Shuttle main engine oxidizer valve/duct system anomalous high amplitude discrete acoustical excitation
Anomalous high frequency pressure fluctuations in the Space Shuttle main engine have been experienced during hot firings. Through diagnostic analysis of hot firing engine data, it was determined that this excitation originated at the main oxidizer valve. The intensity of these fluctuations was such that the main oxidizer valve was partially consumed in fire, experienced fretting, and had seal damage. Delineated in this paper are the associated dynamical phenomena and the methodologies leading toward understanding the excitation mechanism. The results presented demonstrate that the source of the anomalous frequencies was suppressed by a simple fix and all main oxidizer valve damage was terminated.
Schutzenhofer, L. A.↗
A liquid hydrogen experiment as a Shuttle payload
The paper describes the cryogenic fluid management experiment (CFME) as a Shuttle payload. The experiment includes a liquid hydrogen tank containing a fine-mesh screen acquisition device, and a thermal control system consisting of a thermodynamic vent system to intercept heat leak to the hydrogen tank and control tank pressure. Engineering data obtained will be used to establish design criteria for subcritical cryogenic storage and supply tankage.
Eberhardt, R. N.↗
Modular instrumentation system for real-time measurements and control on reciprocating engines
An instrumentation system was developed for reciprocating engines. Among the parameters measured are the indicated mean effective pressure, or theoretical work per cycle, and the mass fraction burn rate, a measure of the combustion rate in the cylinder. These computations are performed from measured cylinder pressure and crankshaft angle and are available in real time for the experimenter. A 100 or 200 consecutive-cycle sample is analyzed to reduce the effect of cyclic variations in the engine. Data are displayed in bargraph form, and the mean and standard deviation are computed. Other instruments are also described.
Rice, W. J.↗
Propulsion system research and development for electric and hybrid vehicles
An approach to propulsion subsystem technology is presented. Various tests of component reliability are described to aid in the production of better quality vehicles. component characterization work is described to provide engineering data to manufacturers on component performance and on important component propulsion system interactions.
Schwartz, H. J.↗
An introduction to the interim digital SAR processor and the characteristics of the associated Seasat SAR imagery
Basic engineering data regarding the Interim Digital SAR Processor (IDP) and the digitally correlated Seasat synthetic aperature radar (SAR) imagery are presented. The correlation function and IDP hardware/software configuration are described, and a preliminary performance assessment presented. The geometric and radiometric characteristics, with special emphasis on those peculiar to the IDP produced imagery, are described.
Wu, C.↗
Mixing effectiveness test of an exhaust gas mixer in a high bypass turbofan at altitude
Thermal mixing effectiveness characteristics of an eighteen lobe, scalloped and unscalloped, partial, forced mixer were measured in a high-bypass turbofan engine. Data were also obtained without the mixer installed, i.e., free mixing. Tests were conducted at four combinations of simulated flight conditions from 0.3 to 0.8 Mach number and from 6,096 meters (20,000 ft) to 13,715 m (45,000 ft) altitude, mixing chamber lengths of L/D=0.52 and 0.65 were tested. For this range of test conditions and mixer configurations, the forced mixing effectiveness varied from 59 to 68 percent. Values of mixing effectiveness and total pressure loss were calculated from temperature and pressure data obtained at the mixer inlet and exhaust nozzle exit.
Cullom, R. R.↗
Low thrust chemical propulsion for orbit transfer of large space structures
For transporting Large Space Structures (LSS) from Low Earth Orbit (LEO) to Geosynchronous Equatorial Orbit (GEO), a variety of low thrust engine cycles have been evaluated for oxygen/hydrogen and oxygen/hydrocarbon propellants. The engine cycles included conventional propellant turbine drives (gas generator, expander, and staged-combustion cycles), turboalternator/electric motor pump drive, and fuel-cell/electric motor pump drive, as well as pressure-fed engines. The thrust chamber cooling limits and the engine cycle limits were established for a range of thrust levels. The candidate engine cycles were analyzed, screened, rated, and two engine cycle/configurations were selected for preliminary engine design. Preliminary engine designs for these two engines were formulated and engine design layouts prepared and parametric engine data generated.
Shoji, J. M.↗
Mixing effectiveness test of an exhaust gas mixer in a high bypass turbofan at altitude
Thermal mixing effectiveness characteristics of an eighteen lobe, scalloped and unscalloped, partial, forced mixer were measured in a high-bypass turbofan engine. Data were also obtained without the mixer installed, i.e. free mixing. Tests were conducted at four combinations of simulated flight conditions from 0.3 to 0.8 Mach number and from 6,096 meters (20,000 ft) to 13,715 m (45,000 ft) altitude. Mixing chamber lengths of L/D = 0.52 and 0.65 were tested. For this range of test conditions and mixer configurations the forced mixing effectiveness varied from 59 to 68 percent. Values of mixing effectiveness and total pressure loss were calculated from temperature and pressure data obtained at the mixer inlet and exhaust nozzle exit.
Cullom, R. R.↗
Traveling-wave maser, closed cycle refrigerator automation
At the present time all traveling-wave maser and closed-cycle refrigerator system (TWM-CCR) and their power supply and helium compressor assemblies are operated manually. Many man-hours are required of highly trained and experienced operators, resulting in high operator cost. Of greater importance are the problems of unpredictable failure and long downtimes. Since field performance is not monitored, system degradation is detected only when it has progressed to the point of catastrophic failure. Without the aid of performance histories, failure diagnosis is arduous and slow. Rational and functional requirements for the TWM-CCR Automation project are the following: (1) to improve reliability and reduce downtime by providing unattended monitor and control, alarm and fault location, failure prediction and self-corrective action; (2) to reduce operator cost by providing automatic tuning and cooldown procedures; and (3) to improve system operations and development by providing the needed engineering data.
Mcneil, J. A.↗
A low-power photovoltaic system with energy storage for radio communications: Description and design methodology
A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.
Chapman, C. P.↗
An experiment to evaluate liquid hydrogen storage in space
The design and verification of a Cryogenic Fluid Management Experiment for orbital operation on the Shuttle is described. The experiment will furnish engineering data to establish design criteria for storage and supply of cryogenic fluids, mainly hydrogen, for use in low gravity environments. The apparatus comprises an LAD (liquid acquisition device) and a TVS (thermodynamic vent system). The hydrogen will be either vented or forced out by injected helium and the flow rates will be monitored. The data will be compared with ground-based simulations to determine optimal flow rates for the pressurizing gas and the release of the cryogenic fluid. It is noted that tests on a one-g, one-third size LAD system are under way.
Eberhardt, R. N.↗
Operating in the age of NASTRAN
The history of the development of the NASTRAN computer program, a general purpose finite element code for structural analysis, is described. The need for research programs to improve analysis of structures, and the writing of a computer program to give numerical solutions for shell behavior, were the impetus for the program design. The use of finite elements to obtain engineering solutions was introduced. The architecture, solution structure, DMAP language, decomposition technique for banded matrices with active columns, general purpose plotter, engineering data inputs, elastic element routines, programmer manuals, of NASTRAN's system design are described.
Butler, T. G.↗
Industry involvement in IPAD through the Industry Technical Advisory Board
In 1976 NASA awarded The Boeing Company a contract to develop IPAD (Integrated Programs for Aerospace-Vehicle Design). This contract included a requirement for Boeing to form an Industrial Technical Advisory Board (ITAB), with members representing major aerospace and computer companies. The purpose of this board was to guide the development of IPAD. The specific goal of IPAD is to increase United States aerospace industry productivity through the application of computers to manage engineering data. This goal clearly is attainable; in fact, IPAD's influence can reach beyond the aerospace industry to many businesses where product development is based on the design-building process. An enhanced IPAD, therefore, is a national asset of significance. The role of ITAB in guiding the development of this system is described.
Swanson, W. E.↗
IPAD: A computer vendor's perspective
The current IPAD technology and the state-of-the-art in computer technology are compared from the point of view of a computer vendor. Issues of engineering data management, distributed architectures, and user interfaces are covered.
Feldman, H. D.↗
Turnkey CAD/CAM systems' integration with IPAD systems
Today's commercially available turnkey CAD/CAM systems provide a highly interactive environment, and support many specialized application functions for the design/drafting/manufacturing process. This paper presents an overview of several aerospace companies which have successfully integrated turnkey CAD/CAM systems with their own company wide engineering and manufacturing systems. It also includes a vendor's view of the benefits as well as the disadvantages of such integration efforts. Specific emphasis is placed upon the selection of standards for representing geometric engineering data and for communicating such information between different CAD/CAM systems.
Blauth, R. E.↗
Anomalous behavior of the Pioneer Venus entry probes during lower descent
Four Pioneer Venus Probe spacecraft entered the Venusian atmosphere on December 9 1978, and descended to the surface while making in situ measurements of chemical composition, structure, and radiative balance. In the lower Venusian atmosphere, a number of anomalous events were noted in some of the scientific instruments and Probe engineering data. Many of these anomalies occurred on each of the Probes at approximately the same altitude. The anomalies are thought to be the result of some unexpected electrical interaction between the Probe and the Venusian atmosphere. This conclusion is based on analysis and testing of similar Probe hardware on the ground. However, the possibility that some anomalies were a result of latent design of manufacturing flaws cannot be ruled out.
Polaski, L. J.↗
A wind tunnel database using RIM
Engineering data base development which has become increasingly widespread to industry with the availability of data management systems is examined. A large data base was developed for wind tunnel data and related model test information, using RIM as the data base manager. The arrangement of the wind tunnel data into the proper schema for the most efficient database utilization is discussed. The FORTRAN interface program of RIM is used extensively in the loading phases of the data base and by the users. Several examples to illustrate how the Wind Tunnel Data base might be searched for specific data items and test information using RIM are presented.
Wray, W. O., Jr.↗