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Results for “THERMAL ABSORPTION”
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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Thermal absorption in seeded grass Semiannual report
Thermal absorption of particle clouds in seeded gas
Vapor-pressure data extrapolated to 1000 atmospheres /1.01 times 108N/m2/ for 13 refractory materials with low thermal absorption cross sections
Predicted high temperature vapor pressure data for refractory materials with low thermal absorption cross sections
Impedance Matched Absorptive Thermal Blocking Filters
We have designed, fabricated and characterized absorptive thermal blocking filters for cryogenic microwave applications. The transmission line filter's input characteristic impedance is designed to match 50Ω and its response has been validated from 0-to-50GHz. The observed return loss in the 0-to-20GHz design band is greater than 20 dB and shows graceful degradation with frequency. Design considerations and equations are provided that enable this approach to be scaled and modified for use in other applications.
Impedance Matched Absorptive Thermal Blocking Filters
We have designed, fabricated and characterized absorptive thermal blocking filters for cryogenic microwave applications. The transmission line filter's input characteristic impedance is designed to match 50 Omega and its response has been validated from 0-to-50GHz. The observed return loss in the 0-to-20GHz design band is greater than 20 dB and shows graceful degradation with frequency. Design considerations and equations are provided that enable this approach to be scaled and modified for use in other applications.
Thermal absorption in seeded gases Final technical report, 13 Feb. 1968 - 12 Feb. 1969
Thermal absorption in aerosol seeded hydrogen and helium gases
Vapor-pressure data extrapolated to 1000 atmospheres for 10 refractory elements with thermal absorption cross sections less than 5 barns
Vapor pressure data to 1000 atmospheres for refractory elements with low thermal absorption
Vapor-pressure data extrapolated to 1000 atmospheres for 10 refractory elements with thermal absorption cross sections less than 5 barns.
Vapor pressure data extrapolated to very high pressures for carbon and refractory metals with thermal absorption cross sections below five barns
Experimental study on a novel three-phase absorption thermal battery with high energy density applied to buildings
Buildings contribute to 75% of total electricity consumption and 80% of peak electricity demand in the United States. A significant portion of building electricity consumption goes to space conditioning. Therefore, using thermal energy storage (TES) to decouple the building electricity consumption and the fluctuating space-conditioning load has significant potential to shift peak electricity demand and improve the stability of the grid. To provide effective TES within the spatial constraints in buildings, a three-phase absorption thermal battery (TATB) system with very high energy storage density was designed and studied. The TATB stores low-temperature heat in hydrate crystals of salts and supports space conditioning through absorption systems. In this study, a benchtop TATB using lithium chloride (LiCl) hydrate crystals as the storage material was tested under practical operating conditions for its energy storage density and discharge rate. We report the TATB successfully generated LiCl hydrate crystals during charging mode and then dissolved the crystals during discharging mode. A material-based energy storage density of 300 kWh/m 3 (specific energy of 903 kJ/kg) was achieved with a discharge rate of up to 1.3 kW thermal energy. The test results verified the high performance of the TATB and encouraged further development of this technology.
A description of the correlated k distributed method for modeling nongray gaseous absorption, thermal emission, and multiple scattering in vertically inhomogeneous atmospheres
A radiative transfer method for treating nongray gaseous absorption and thermal emission in vertically inhomogeneous multiple scattering atmospheres is described. Probability density distributions of absorption coefficient strength are derived from line-by-line calculations to construct line-by-line and band model based k distributions. The monotonic ordering of absorption coefficient strengths in these k distributions implicitly preserves the monochromatic structure of the atmosphere at different pressure levels, thus simulating monochromatic spectral integration at a fraction of the line-by-line computing cost. The k distribution approach also permits accurate modeling of overlapping absorption by different atmospheric gases and accurate treatment of nongray absorption in multiple scattering media. It is shown that the correlated k distribution method is capable of achieving numerical accuracy to within 1 percent of cooling rates obtained with line-by-line calculations throughout the troposphere and most of the stratosphere.
Cryogenic Thermal Absorptance Measurements on Small-Diameter Stainless Steel Tubing
The Mid Infrared Instrument (MIRI) on the James Webb Space Telescope includes a mechanical cryocooler which cools its detectors to their 6 Kelvin operating temperature. The coolant gas flows through several meters of small-diameter stainless steel tubing, which is exposed to thermal radiation from its environment. Over much of its length this tubing is gold-plated to minimize the absorption of this radiant heat. In order to confirm that the cryocooler will meet MIRI's requirements, the thermal absorptance of this tubing was measured as a function of its environment temperature. We describe the measurement technique and present the results.
ABSORPTION OF THERMAL RADIATION IN V-GROOVE CAVITIES
Thermal radiation absorption in v-groove cavities
Absorptance of thermal radiation by cryodeposit layers.
Thermal radiation absorptance of cryodeposit condensed upon thin metallic wall
Solar absorptance and thermal emittance of some common spacecraft thermal-control coatings
Solar absorptance and thermal emittance of spacecraft materials are critical parameters in determining spacecraft temperature control. Because thickness, surface preparation, coatings formulation, manufacturing techniques, etc. affect these parameters, it is usually necessary to measure the absorptance and emittance of materials before they are used. Absorptance and emittance data for many common types of thermal control coatings, are together with some sample spectral data curves of absorptance. In some cases for which ultraviolet and particle radiation data are available, the degraded absorptance and emittance values are also listed.
EMISSION AND ABSORPTION OF THERMAL RADIO RADIATION
Emission and absorption of thermal radio radiation
Thermal radiation absorption in rectangular- groove cavities
Thermal radiation absorption in rectangular groove cavities
Thermal Radiation Absorption in Rectangular-Groove Cavities
Thermal radiation absorption in rectangular-groove cavities
A survey of solar absorptance and thermal emittance instrumentation at Goddard Space Flight Center
Optical and thermal method of measuring solar absorptance and thermal emittance