CONJUGATE NUMERICAL INVESTIGATION OF A MINIATURE FLAT-PLATE EVAPORATOR OF A CAPILLARY PUMPED LOOP FOR ELECTRONICS COOLING

A capillary pumped loop (CPL) is a two-phase thermal control device applied in cooling electronic devices. A two-dimensional conjugate numerical model of a miniature flat-plate capillary evaporator is presented in order to describe liquid and vapor flow, heat transfer and phase change in the porous wick structure, liquid flow and heat transfer in the compensation cavity and heat transfer in the vapor grooves and the metallic wall. The entire evaporator is solved with the SIMPLE algorithm as a conjugate problem. The shape and location of the vapor-liquid interface inside the wick are calculated, and a side wall effect heat transfer limit is introduced to estimate the evaporator’s heat transport capability. The influence of various wall materials on the evaporator’s performance is discussed in detail. The results suggest that an evaporator with a combined wall is capable of dissipating high heat flux and stabilizing the temperature of electronic devices at a moderate temperature level.