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Accession Number:
AD0607891
Title:
NON-EVACUATED CRYOGENIC THERMAL INSULATION STUDIES.
Corporate Author:
AEROJET-GENERAL CORP AZUSA CALIF
Report Date:
1964-09-01
Abstract:
The thermal accommodation coefficient was studied for its application to very fine powders, and its probable effect on heat transfer through powders was evaluated. On the basis of the literature survey, a heat-transfer model was devised which depicts heat as being transported by three heat-transfer modes operating independently and in parallel. Experimental data was gathered on the thermal conductivity of a mixture of carbon black and silica powder. Data were collected for several powder mean temperatures and densities, with helium, neon, and nitrogen used as interstitial gases at atmospheric pressure. The heat-transfer model was compared to the experimental data, with good correlation. Analysis of the experimental data showed that the thermal conductivity of a powder is primarily dependent upon the effective gas thermal conductivity, which may be regulated to some extent by the size of the interstitial pore. It was also shown that heat transfer through interparticle contact may be very large if the interstitial gas is adsorbed upon the powder particles. Both the theoretical model and the experimental data indicate that the accommodation coefficient influences heat transport through a powder bed in only a minor way. Author
Descriptive Note:
Summary technical rept. for 15 Jul 63-30 Jun 64,
Pages:
0094
Contract Number:
AF33 657 11200
File Size:
0.00MB
