Natural Environment Criteria for the NASA Space Station Program. Second Edition
Atmospheric models, astrodynamic constants, radiation, and magnetic fields for Earth, Moon, Mars, Venus, and interplanetary space
Weidner, D. K.↗
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Results for “programming model”
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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Evaluation test program, valve, explosive actuated, normally closed Pyronetics model 1400
Evaluation tests of the explosive actuated normally closed valves used to control and isolate hydrazine flow in the TOPS spacecraft, are presented. The malfunctions, modifications, service life, and reliability of the valve are also outlined.
Avalos, E.↗
Advanced communication system time domain modeling techniques ASYSTD software description. Volume 1: Program users guide
A computer program is described which is primarily designed to simulate the transient behavior of communications systems.
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Space shuttle hypergolic bipropellant RCS engine design study, Bell model 8701
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.
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Liquid rocket combustion computer model with distributed energy release. DER computer program documentation and user's guide, volume 1
A computer program for analyzing rocket engine performance was developed. The program is concerned with the formation, distribution, flow, and combustion of liquid sprays and combustion product gases in conventional rocket combustion chambers. The capabilities of the program to determine the combustion characteristics of the rocket engine are described. Sample data code sheets show the correct sequence and formats for variable values and include notes concerning options to bypass the input of certain data. A seperate list defines the variables and indicates their required dimensions.
Combs, L. P.↗
Space shuttle maneuvering engine reusable thrust chamber program. Task 11: Stability analyses and acoustic model testing data dump
The combustion stability characteristics of engines applicable to the Space Shuttle Orbit Maneuvering System and the adequacy of acoustic cavities as a means of assuring stability in these engines were investigated. The study comprised full-scale stability rating tests, bench-scale acoustic model tests and analysis. Two series of stability rating tests were made. Acoustic model tests were made to determine the resonance characteristics and effects of acoustic cavities. Analytical studies were done to aid design of the cavity configurations to be tested and, also, to aid evaluation of the effectiveness of acoustic cavities from available test results.
Oberg, C. L.↗
Blade row dynamic digital compression program. Volume 2: J85 circumferential distortion redistribution model, effect of Stator characteristics, and stage characteristics sensitivity study
The results of dynamic digital blade row compressor model studies of a J85-13 engine are reported. The initial portion of the study was concerned with the calculation of the circumferential redistribution effects in the blade-free volumes forward and aft of the compression component. Although blade-free redistribution effects were estimated, no significant improvement over the parallel-compressor type solution in the prediction of total-pressure inlet distortion stability limit was obtained for the J85-13 engine. Further analysis was directed to identifying the rotor dynamic response to spatial circumferential distortions. Inclusion of the rotor dynamic response led to a considerable gain in the ability of the model to match the test data. The impact of variable stator loss on the prediction of the stability limit was evaluated. An assessment of measurement error on the derivation of the stage characteristics and predicted stability limit of the compressor was also performed.
Tesch, W. A.↗
Model for refining operations
Program predicts production volumes of petroleum refinery products, with particular emphasis on aircraft-turbine fuel blends and their key properties. It calculates capital and operating costs for refinery and its margin of profitability. Program also includes provisions for processing of synthetic crude oils from oil shale and coal liquefaction processes and contains highly-detailed blending computations for alternative jet-fuel blends of varying endpoint specifications.
Dunbar, D. N.↗
Three dimensional thermal pollution models. Volume 3: Free surface models
Two sets of programs, named Nasum 2 and Nasum 3 are presented in detail. Nasum 2 is a far field formulation and is used without including the plant thermal discharge. Nasum 3 uses horizontal stretching to provide higher resolution at thermal discharge joints; and includes far field influences such as varying tides and ambient currents far from point of discharge.
Lee, S. S.↗
INDES User's guide multistep input design with nonlinear rotorcraft modeling
The INDES computer program, a multistep input design program used as part of a data processing technique for rotorcraft systems identification, is described. Flight test inputs base on INDES improve the accuracy of parameter estimates. The input design algorithm, program input, and program output are presented.
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Cube-Corner Retroreflector Modeling
Collection of computer programs analyzes arrays of optical cube corners used in laser ranging. Programs compute impulse-response and interference effects of reflected pulses from optical cube corners and calculates interference-effects histogram and far-field diffraction patterns.
Kirk, J. G.↗
Planetary atmospheres program
Chemical and physical models of the Jovian subnebula are addressed. Halide cloud condensation and volatile element inventories on Venus and considered. Computation methods for isolated grain condensation behavior are examined.
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The GRASP 3: Graphical Reliability Analysis Simulation Program. Version 3: A users' manual and modelling guide
Alternate definitions of system failure create complex analysis for which analytic solutions are available only for simple, special cases. The GRASP methodology is a computer simulation approach for solving all classes of problems in which both failure and repair events are modeled according to the probability laws of the individual components of the system.
Phillips, D. T.↗
A flexible computer aid for conceptual design based on constraint propagation and component-modeling
The Rubber Airplane program, which combines two symbolic processing techniques with a component-based database of design knowledge, is proposed as a computer aid for conceptual design. Using object-oriented programming, programs are organized around the objects and behavior to be simulated, and using constraint propagation, declarative statements designate mathematical relationships among all the equation variables. It is found that the additional level of organizational structure resulting from the arrangement of the design information in terms of design components provides greater flexibility and convenience.
Kolb, Mark A.↗
Energy Efficient Engine exhaust mixer model technology report addendum; phase 3 test program
The Phase 3 exhaust mixer test program was conducted to explore the trends established during previous Phases 1 and 2. Combinations of mixer design parameters were tested. Phase 3 testing showed that the best performance achievable within tailpipe length and diameter constraints is 2.55 percent better than an optimized separate flow base line. A reduced penetration design achieved about the same overall performance level at a substantially lower level of excess pressure loss but with a small reduction in mixing. To improve reliability of the data, the hot and cold flow thrust coefficient analysis used in Phases 1 and 2 was augmented by calculating percent mixing from traverse data. Relative change in percent mixing between configurations was determined from thrust and flow coefficient increments. The calculation procedure developed was found to be a useful tool in assessing mixer performance. Detailed flow field data were obtained to facilitate calibration of computer codes.
Larkin, M. J.↗
Middle Atmosphere Program. Handbook for MAP. Volume 31: Reference models of trace species for the COSPAR international reference atmosphere
A set of preliminary reference atmosphere models of significant trace species which play important roles in controlling the chemistry, radiation budget, and circulation patterns of the atmosphere were produced. These models of trace species distributions are considered to be reference models rather than standard models; thus, it was not crucial that they be correct in an absolute sense. These reference models can serve as a means of comparison between individual observations, as a first guess in inversion algorithms, and as an approximate representation of observations for comparison to theoretical calculations.
Keating, G. M.↗
Eleven-Species Thermochemical Model Of Air
SPECIES program computes thermodynamic and transport properties and equilibrium constants. Uses least-squares polynomial curve fits of most accurate data available to provide requested values more quickly than table-lookup methods. Subroutines computing transport coefficients and collision cross sections include additional code to correct for any electron pressure when working with ionic species. Species represented: diatomic nitrogen, diatomic oxygen, atomic nitrogen, atomic oxygen, nitric oxide, ionized nitric oxide, free electron, ionized atomic nitrogen, ionized atomic oxygen, ionized diatomic nitrogen, and ionized diatomic oxygen. Written in FORTRAN 77.
Thompson, Richard A.↗
Transient periodicities in X-ray-active red dwarfs - First results from Mount Cuba and interpretation with an oscillating loop model
Results from a program at the Mount Cuba Astronomical Observatory to optically monitor transient periodicities in flare stars are reported. The data are analyzed for periodicities by means of a modified autocorrelation approach. A randomization technique is used to assess the statistical significance of periods. In AD Leonis, variability with amplitude 0.4 percent and a period of 4.1 min was detected during one run on March 6, 1991: the probability that this periodicity is due to chance is 10 exp -5. Further observations obtained on AD Leo within 1-2 hr on the same night showed no significant variability (0.01). It is shown that optical periodicities of the sort detected may be interpreted as arising from oscillations in coronal loops.
Mullan, D. J.↗