Experimental Investigation of the Feasibility of Using a Liquid Metal as a Variable Conductance Radiator for Space Applications

Abstract

The feasibility of using a liquid metal with a high thermal conductivity as a functional fluid for realizing a variable conductance radiator (VCR) for space applications was proposed and investigated. The variable thermal conductivity of the radiator can be achieved by moving the liquid metal using a magneto-hydraulic pump between the two reservoirs in accordance with the temperature requirements of the on-board equipment. The liquid metal radiator proposed in this study is much more effective for saving heater power under cold condition while effectively dissipating heat to deep space under hot condition. The thermal behavior of the liquid metal radiator was demonstrated using the ambient thermal tests under cooling and insulation modes of the radiator. The performance of the proposed VCR was evaluated by comparing it with that of the conventional radiator whose conductivity value is fixed. The proposed radiator using the liquid metal was more effective than conventional radiator for suppressing the rate of increase of temperature for the heat dissipation unit in the cooling mode and for saving additional heater power by removing the liquid metal in the insulation mode.