Experimental investigation on thermal conductivity of cryogenic frost under forced convection

Abstract

An experimental study on the phase change occurring on a cryogenic cooling surface was conducted under forced convection conditions. The mass and surface temperature of frost and the heat flux at the cooling surface were measured in the experiment. The heat and mass transfer analogy was investigated under cryogenic conditions. The mass estimated under various experimental conditions using the modified analogy differed by up to 8% from the experimentally measured mass. The density and thermal conductivity of frost at cryogenic temperatures were lower than those of general-low temperature frost; the dimensionless correlations of density and thermal conductivity of frost were derived via regression analysis. The calculated frost density and thermal conductivities were differed from the measured value by up to 9% and 11%, respectively. Therefore, a model was built to predict the heat and mass transfer and improve the thermal performance on the cooling surfaces of various cryogenic devices using the presented frost density and thermal conductivity correlations.