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Results for “Radiator gas”

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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Atmospheric heating of meteors.

A theoretical model of the radiating metallic gas produced about an iron meteor entering the earth's atmosphere is discussed. Numerical results are presented for a 0.1 cm diameter iron meteor traveling at 15 km/sec at an altitude of 100 km above the earth. It is shown that collisions between the expanding iron gas and the air molecules produce a radiating gas shell a few meters thick which is located many meters ahead of the meteor core. Temperature, pressure, and density distributions are presented as functions of radial distance and angle for several initial meteor conditions.

Harwell, K. E.↗
NASA NTRS1975

Payload dose rate from direct beam radiation and exhaust gas fission products

A study was made to determine the dose rate at the payload position in the NERVA System (1) due to direct beam radiation and (2) due to the possible effect of fission products contained in the exhaust gases for various amounts of hydrogen propellant in the tank. Results indicate that the gamma radiation is more significant than the neutron flux. Under different assumptions the gamma contribution from the exhaust gases was 10 to 25 percent of total gamma flux.

Capo, M. A.↗
NASA NTRS1993

Radiative Cooling of Warm Molecular Gas

We consider the radiative cooling of warm (T >= 100 K), fully molecular astrophysical gas by rotational and vibrational transitions of the molecules H2O, CO, and H2. Using an escape probability method to solve for the molecular level populations, we have obtained the cooling rate for each molecule as a function of temperature, density, and an optical depth parameter. A four-parameter expression proves useful in fitting the run of cooling rate with density for any fixed values of the temperature and optical depth parameter. We identify the various cooling mechanisms which are dominant in different regions of the astrophysically relevant parameter space. Given the assumption that water is very abundant in warm regions of the interstellar medium, H2O rotational transitions are found to dominate the cooling of warm interstellar gas over a wide portion of the parameter space considered. While chemical models for the interstellar medium make the strong prediction that water will be produced copiously at temperatures above a few hundred degrees, our assumption of a high water abundance has yet to be tested observationally. The Infrared Space Observatory and the Submillimeter Wave Astronomy Satellite will prove ideal instruments for testing whether water is indeed an important coolant of interstellar and circumstellar gas.

Neufeld, David A.↗
DOE OSTI2025

X-ray absorption spectroscopy measurements of radiatively ionized argon gas

X-ray absorption spectroscopy is a diagnostic tool that can characterize the temperature and ionization state of a plasma. This technique requires experiments to characterize the platform, careful data calibration, and comparison with atomic models to understand the plasma parameters. We performed ionizing radiation wave experiments at the OMEGA Laser Facility that used an ∼ 80 eV X-ray source to heat an Argon (Ar) gas cell at fill pressures of 3 atm. To diagnose the Ar plasma, we used a capsule backlighter offset 10 mm from the gas cell, to produce X-rays that were absorbed by the ionized Ar gas. The absorption analysis was calibrated using the significant line structure in the backlighter spectrum, which served as independent energy fiducials enabling definitive measurements of a 50-eV shift in the energy of the Ar K-edge due to ionization. We compare the measured absorption spectra to two independent atomic models, PrismSPECT and SCRAM, and show that the observed K-edge shift in the heated gas is consistent with ionization up to Ar 4+ and temperatures of 10 eV.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1990

Negative radiation in partially ionized gas

A stationary, nonlinear collisional-radiative model for high-temperature atomic oxygen is presented. Populations of negative ions, electrons, positive ions and excited atoms and intensities of spectral, continuum and dielectronic recombination radiation are calculated in a wide range of conditions. Calculated total continuum emission is in good agreement with existing measurements. The contribution of the negative ion emission to the total continuum emission is found to be significant.

Soon, W. H.↗
NASA NTRS1993

Effects of particulate radiation on premixed gas flames

Observations of the effect of the addition of fine solid particles to weakly combustible methane-air mixtures are reported. Burning rates, pressure rise, and thermal characteristics are found to exhibit nonmonotonic trends with increasing particle loading. These results are interpreted in terms of the effects of augmentation of radiant loss at small particle loadings and re-absorption of emitted radiation at larger loadings. It is suggested that in sufficiently large systems, flammability limits might not exist because of this reabsorption effect.

Abbud-Madrid, Angel↗
NASA NTRS1973

Radiation pyrometer for gas turbine blades

A turbine blade temperature measuring system for liquid oxygen turbopumps is reported. The system includes a three mode, two-input optical signal processor, interconnecting cable, and four sensor heads. Two of the heads are aperture type, while the other two are lens type. This system is applicable to a temperature range of 1400 to 2200 F.

Rohy, D. A.↗
NASA NTRS1983

Orbiter cargo bay thermal environment data

The orbiter cargo bay thermal environment data is presented. Measurements include: insulation surface temperatures, wire tray surface temperatures, sill longeron temperatures, gas temperatures, radiator temperatures, and gas pressure.

Brown, R. G.↗
NASA NTRS2005

Unitized Regenerative Fuel Cell System Gas Storage-Radiator Development

High-energy-density regenerative fuel cell systems that are used for energy storage require novel approaches to integrating components in order to preserve mass and volume. A lightweight unitized regenerative fuel cell (URFC) energy storage system concept is being developed at the NASA Glenn Research Center. This URFC system minimizes mass by using the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The waste heat generated by the URFC stack during charging and discharging is transferred from the cell stack to the surface of each tank by loop heat pipes, which are coiled around each tank and covered with a thin layer of thermally conductive carbon composite. The thin layer of carbon composite acts as a fin structure that spreads the heat away from the heat pipe and across the entire tank surface. Two different-sized commercial-grade composite tanks were constructed with integral heat pipes and tested in a thermal vacuum chamber to examine the feasibility of using the storage tanks as system radiators. The storage tank-radiators were subjected to different steady-state heat loads and varying heat load profiles. The surface emissivity and specific heat capacity of each tank were calculated. In the future, the results will be incorporated into a model that simulates the performance of similar radiators using lightweight, spacerated carbon composite tanks.

Burke, Kenneth A.↗