Effects of Outlet Width and Channel Configuration on the Thermohydraulic Performance of Wedge-Shaped Manifold Microchannels

This study numerically investigates the effects of manifold outlet width and lower-layer microchannel configuration on the thermohydraulic performance of a wedge-shaped manifold microchannel heat sink for high-heat-flux electronic cooling. A three-dimensional steady conjugate heat-transfer model was established in Ansys Fluent and assessed through grid-independence analysis and comparison with experimental pressure-drop and coolant-temperature-rise data. Simulations were conducted at inlet velocities of 1.0, 1.15, and 1.3 m/s to evaluate the average and maximum heat-source temperatures, temperature uniformity, pressure drop, thermal resistance, and performance evaluation criterion (PEC). Within the investigated manifold outlet-width range of 0.62–0.71 mm, increasing the outlet width produced concurrent reductions in the average and maximum heat-source temperatures and pressure drop, while improving the temperature uniformity of the heated surface. Among the outlet-width cases examined, 0.71 mm provided the most favorable thermohydraulic performance within the tested range. The influence of channel configuration depended on the evaluation objective. The wavy channel (WC) yielded the lowest heat-source temperatures and thermal resistance and therefore exhibited the best thermal performance among the investigated configurations. By contrast, the trapezoidal channel (TrC) maintained the highest PEC over the investigated inlet-velocity range and reached a maximum value of 1.140 at 1.3 m/s, indicating the most favorable balance between heat-transfer enhancement and hydraulic penalty. These results demonstrate that manifold outlet width and channel configuration should be selected jointly according to the required balance between temperature control and hydraulic performance.