Measurement of the heat transfer characteristics of gas flow in fine channel heat exchangers used for microminiature refrigerators

Abstract

The heat transfer characteristics have been measured for the flow of gas in the fine channels of the heat exchangers used for microminiature J-T refrigerators. The test channels were fabricated using a photolithographic technique similar to that used for the fabrication of the refrigerators. The unique features of such channels are their asymmetric roughness, their large relative roughness and a large variation of the heat flux and temperature over the walls of the channels. The tests involved both laminar and turbulent flow regimes. The results we have obtained are useful for designing heat exchangers in microminiature refrigerators.