Analysis of thermal performance and pressure loss of subcooled flow boiling in manifold microchannel heat sink

Abstract The manifold microchannel (MMC) heat sink for high-heat-flux removal in next-generation microelectronic system has received a significant attention recently. A numerical study is performed to analyze thermal performance and pressure loss of subcooled flow boiling in an MMC unit cell model. On the basis of OpenFOAM package, a new solver is developed for solving subcooled flow boiling and solid-fluid heat transfer. The simple coupled volume of fluid with level set (S-CLSVOF) method is used to capture the liquid-vapor interface during phase change. After validating the numerical approach with experimental data, effects of microchannel width wc and fin width wf on average chip wall temperature and inlet-to-outlet pressure drop are discussed. Seven MMC samples with different size of channel widths and fin widths are studied at inlet volume flow rates of 19, 31 and 42 mL/min as wall heat flux is fixed at 400 W/cm2. The results indicate that decreasing wc and wf will lead to low average wall temperature on the heated wall, but pressure drop between inlet and outlet surfaces will rise dramatically. When the total number of channels of the MMC heat sink remains unchanged, increasing wc leads to decreasing wf; the thermal resistance of the MMC heat sink is gradually increased while the pressure drop is reduced (e.g. +0.16 °C/W, -656 kPa at 42 mL/min).