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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

Time Averaged Pressure Measurement in Fundamentally Unsteady Pressure Gain Combustion Systems

Experimental results and analysis are presented on a technique for obtaining time averaged pressure in the harsh and highly unsteady environment of a pressure gain combustor. The technique utilizes a long, narrow, stand-off tube leading from the measurement point to a pressure transducer. The tube damps the fluctuations (which may result from strong shocks and/or detonations) and thermally isolates the transducer. The damping must be sufficient to ensure that net gasdynamic work exchange does not occur on the fluid in the stand-off tube, and it must be linear to insure that the time-averaged pressure at the transducer end is the same as that at the combustor end. The paper presents experimental and analytical results from two rigs which indicate that, using certain stand-off tube dimensions, these criteria are met. Physical rational for the tube dimensions (i.e., guidelines) are also presented.

detonation↗
NASA NTRSDate not supplied

Cryogenic Extension of NASA Species Polynomials Using Hydrogen and Oxygen at Stoichiometry

NASA has been conducting research in Rotating Detonation Rocket Engines (RDREs) for several years. A recent test at the Marshall Spaceflight Center has successfully shown operation of a RDRE that ran for 251 seconds which had combustion chamber cryogenic inlet conditions [1]. However, an overall pressure gain was not observed in the performance of the engine. Such an indication could mean an optimal chamber design is yet to be discovered. Such a design could significantly reduce parasitic pressure loses and improve overall engine efficiency beyond that of conventional rockets. To investigate different chamber configurations, new CFD capability is needed to accurately capture cryogenic thermophysical and transport property data. Such an effort is currently part of NASA’s Early Career Initiative (ECI) program. This paper focuses on the thermophysical property mixture model approach that makes use of NASA’s polynomial fits of species and another cryogenic model chosen from NIST’s Refprop program. Presented in this paper are results of a 1D denotation CFD simulation of stoichiometric Hydrogen and Oxygen mixture at a cryogenic upstream condition.

Combustion↗
NASA NTRSDate not supplied

Cryogenic Extension of NASA Species Polynomials Using Hydrogen and Oxygen at Stoichiometry

The Helmholtz free energy for a mixture has been used in many chemistry and combustion studies for mixtures. An approach is described where polynomial fits intended for a thermally perfect ideal gases can be modified and implemented into a Helmholtz free energy model, such as those used by NIST in their REFPROP program. However, the limitation of the polynomial fits must be respected and should only used in a valid temperature interval where the flow field can be treated as a thermally perfect ideal gas when these species are present. This approach can allow a CFD simulation to have cryogenic regions of a flow field where high fidelity cryogenic species models are needed and allows for the use of species in other areas at higher temperatures where combustion species do not have such a model available or is not needed. Presented in the paper are CFD 1D detonation wave and species mass fraction simulation results which have cryogenic upstream conditions of Hydrogen and Oxygen at stoichiometry.

Combustion↗
NASA NTRSDate not supplied

CEA2022: A Modernization of NASA Glenn’s Software CEA (Chemical Equilibrium with Applications)

The software program “Chemical Equilibrium with Applications” (CEA) is used to solve chemical equilibrium, and compute thermodynamic and transport properties of the resulting mixture, and also has special solvers dedicated to rocket, shock, and detonation problems. We have recently completed a full re-write of CEA with modernization and improvements, called “CEA2022”. In this paper, we will give an overview of CEA2022’s features, and discuss some of the fundamental equations used by CEA2022, as well as the fundamental assumptions, in order to provide users with a complete understanding of the software’s methodology. Several enhancements have been made to the software, including modern software development practices, interface improvements, and additional features. The feature enhancements include: running cases in parallel with thread safe solves, thermodynamic and transport database updates, and allowing for negative and inert reactants. In terms of interface improvements, we have made CEA a reusable library by adding APIs for multiple languages, including Python, Matlab, Excel, Fortran, and C. The subroutine interface allows for integration with other applications, including flow-solver integration (i.e. with CFD). We also compare results between CEA2022 and the previous version (CEA2) as a validation of the new software.

chemical equilibrium↗
NASA NTRS2026

Updates and Modernization of the Chemical Equilibrium with Applications (CEA) Code

NASA’s Chemical Equilibrium with Applications (CEA) code is a foundational tool for propulsion system analysis. It provides equilibrium chemistry, rocket performance, shock, and detonation calculations used across NASA and the broader aerospace community. NASA Engineering and Safety Center (NESC) Activity TI-22-01730 modernized the legacy CEA2 Fortran code into CEA v3, a Fortran 2008, object-oriented software package with expanded interface support, updated thermochemical data, improved maintainability, and substantially improved workflow integration. The modernized code preserves backward compatibility with legacy CEA input workflows while enabling direct use from modern analysis environments, including Python, C, MATLAB, and automated design studies.

Combustion↗
NASA NTRS1963

Ninth Symposium (International) on Combustion

The Ninth Symposium (International) on Combustion was held at Cornell University, Ithaca, New York, August 27 to September 1, 1962, under the auspices of the Combustion Institute. Registration was in excess of 600, with more than 100 attending from Australia, Belgium, Canada, France, Germany, Great Britain, Hungary, Israel, Italy, Japan, Netherlands, Spain and Sweden. Over 200 papers were submitted for consideration, of which 121 were placed on the program and 108 printed in the Proceedings. Two Discussions (Detonations, organized by Dr. D. R. White, General Electric Research Laboratory; Fundamental Flame Processes, organized by Dr. W. H. Avery, APL/The Johns Hopkins University) occupied 4 half-day sessions each. Preprints of all Discussions papers were available several weeks prior to the Symposium. Three Colloquia (Modeling Principles, organized by Professor D. 13. Spalding, Imperial College; Reactions and Phase Changes in Supersonic Plow, organized by Professor P. P. Wegener, Yale University; Reciprocating Engine Combustion Research, organized by Professor E. S. Starkman, University of California) occupied 2 or 3 half-day sessions each. Contributed Papers in many areas of the combustion field were presented in 10 half-day sessions. Comments on nearly every paper are included in the Proceedings.

Gas phase↗
NASA NTRS1966

Explosive force of primacord grid forms large sheet metal parts

Primacord which is woven through fish netting in a grid pattern is used for explosive forming of large sheet metal parts. The explosive force generated by the primacord detonation is uniformly distributed over the entire surface of the sheet metal workpiece.

Source record↗
NASA NTRS1968

Piezoelectric pressure pickup

Piezoelectric pressure pickups for measuring pressures of gases and liquids behind incident and reflected shock waves, and detonation studies

Gusev, M. V.↗