Experimental and numerical investigation of a multi-pass branching microchannel heat sink

•Design and fabrication of multi-pass branching microchannel heat sink is described.•Experiments and simulations were performed to study heat sink performance.•Unit thermal resistance and pressure drop measurements agree with numerical results.•Favorable thermal/flow performance achieved via multi-pass branching microchannels.•Design approach may be used to develop novel heat transfer and fluid flow structures.

This paper reports the results from an experimental and numerical investigation of a multi-pass branching microchannel heat sink for high heat flux applications. The design and fabrication of the heat sink and experimental facility is described. The unit thermal resistance and pressure drop performance of the cold plate is determined for a range of flow conditions, 1070 < Re < 6370, using a single-phase ethylene-glycol/water coolant. Experiments are followed by local conjugate heat transfer and global flow simulations of the test piece. Comparisons are made between measured data, numerical results, and analytical predictions. The results from the investigation confirm the adequacy of the approach and reveal the effects of the multi-pass branching microchannel architecture on the performance of the cold plate. The heat sink is shown to provide favorable cooling performance with low unit thermal resistance (0.34 cm2 K/W) and pressure drop (19.5 kPa at 1 L/min) for high-power-density (of order 100 W/cm2) electronics applications.