Influence of obstruction's unilateral length on flow and heat transfer performance of micro-channel heat sinks with flow obstructions

As the density and integration of electronic equipment continue to increase, it becomes necessary to build micro-channel heat sinks with more efficient cooling effects to solve the heat removal issue. This paper proposes a series of obstructions established on a smooth water-cooled microchannel and analyzes the heat transfer and flow performance from the viewpoint of fluid dynamics. By adjusting the unilateral side length of the obstructions, the simulation conducted a comparative analysis between the seven different obstruction shapes and smooth micro-channel heat sinks, focusing on Nusselt number, thermal resistance, and pressure loss across a range of Reynolds numbers. The findings demonstrate that the heat dissipation capacity of micro-channel heat sinks with obstructions is consistently superior to that of the smooth heat sink, and the performance of these heat sinks is affected by the length of unilateral side of the obstructions. With no consideration of pumping power, the paper argues that the heat sink with obstructions, specifically those with a unilateral side length of 0.06 mm, has the best heat dissipation capacity at Reynolds numbers below 460. At this Reynolds number, the Nusselt number increases by 99% and the thermal resistance decreases by 33% compared to a smooth micro-channel heat sink. However, when the pumping power is considered, the heat sink with obstructions whose unilateral sides are the shortest has the best performance due to its minimal pressure loss. While meeting the thermal resistance requirement of 0.033, it requires only one-fourth of the pumping power needed by a heat sink with obstructions whose unilateral sides are longest.