Numerical analysis on the thermal hydraulic performance of a composite porous vapor chamber with uniform radial grooves

Composite porous vapor chamber (CPVC) with good thermal performance in temperature uniformity and high heat-flux limit was recently developed, and its wick structure consisted of a condenser wick and an evaporator wick with uniform radial grooves. However, the underlying mass and heat transfer mechanisms of the CPVC are unclear, hindering its further development. A simplified numerical model is presented in this paper to study the thermal hydraulic performance of the CPVC. By analyzing of the thermal performance, liquid/vapor velocity and pressure distributions of the CPVC with the input heat flux of 6 x 10(5)-28 x 10(5) W/m(2), the influence of the wick structures, the wick porosity configuration and the powder size on the thermal hydraulic performance of the CPVC is investigated. Results show that the wicks can provide radial multi-artery channels for liquid backflow and heat conductive passages for heat transfer. The wick porosity affects the performance of the CPVC more than the powder size does. To obtain better performance, the configuration of the evaporator wick porosity and the condenser wick porosity should make the maximum pressure drop in the wicks slightly less than the maximum capillary pressure. However, the optimal porosity configuration varies with the powder size. Larger powder size results into smaller optimal porosity, and vice versa. In addition, the wick porosities should be as close as possible to the lower bound of their range. To facilitate the fluid flowing through the multi-artery channels, the evaporator wick porosity should be slightly larger than the condenser wick porosity. The work is useful for optimizing CPVC. (C) 2019 Elsevier Ltd. All rights reserved.