Energy accommodation coefficient extracted from acoustic resonator experiments
Felix Sharipov, Michael R. Moldover
We review values of the temperature jump coefficient zeta_T determined from measurements of the acoustic resonance frequencies f_acoust of helium-filled and argon-filled, metal-walled, quasi- spherical cavities near ambient temperature. We combine these values of zeta_T with literature data for tangential momentum accommodation coefficient (TMAC) and the Cercignani-Lampis model of the gas-surface interaction to obtain measurement-derived values of the normal energy accommodation coefficient (NEAC). We found that NEAC ranges from 0 to 0.1 for helium and from 0.61 to 0.85 for argon at ambient temperature. We suggest measurements of f_acoust of gas- filled, cylindrical cavities and of the non-radial modes of quasi-spherical cavities might separately determine TMAC and NEAC. Alternatively, TMAC and NEAC could be determined by measuring the heat transfer and momentum transfer between parallel rotating discs at low pressure.