Two-Phase Heat Dissipation Utilizing Porous-Channels of High-Conductivity Material

The results of an experimental study of two-phase heat dissipation in high-conductivity porous channel heat sinks are presented. Porous channels of various sizes were fabricated using sintered copper particles inside rectangular copper channels with base dimensions of 25 mm by 25 mm, either 3 or 10 mm in height. The experiments were conducted using subcooled water as the working fluid and test conditions ranged from an inlet temperature of 85 to 95°C, inlet pressures of 1.062 to 1.219 bars, flow rates of 22.5 to 150 ml/min, and heat fluxes of 10 to 25 W/cm². The experimental results were compared to the results predicted using a previously developed numerical model. For water with inlet subcooling in the range of 6.6 to 10.8°C, heat transfer coefficients for open channel flow were increased from 1.25 to 1.94 W/cm^2°C to 1.79 to 3.33 W/cm^2°C, or a 43 to 142 percent improvement through the use of porous channels with mean particle diameters of 0.97, 0.54, 0.39, or 0.33 mm. The results indicate that the high thermal conductivity of the porous material and the large solid-fluid contact area combine to create a highly effective, two-phase heat sink, which may provide an effective mechanism for cooling high heat flux microelectronics.