The Paper involves experimental and numerical heat transfer analyses of four pin-fin cooling configurations in a rectangular channel. Two design concepts were studied with two separate pin-fin (cylindrical and triangular) geometries. The first design includes a single-wall pin-fin configuration where the coolant flows through an array of full-length cylindrical (PF) and triangular pin fins (TF). The second configuration involves a double-wall pin-fin–jet configuration where the coolant jet impinges on the target wall, then flows through the array of partial-length cylindrical pin fins with jets (PFC) and partial-length triangular pin fins with jets (TFC). IR thermography was used to measure the steady state wall temperature of the target surface to estimate the overall cooling effectiveness $\varphi$. A transient heat transfer experiment was conducted to evaluate the internal heat transfer coefficient from the transient wall temperature. It is found that the double-wall pin-fin–jet (PFC and TFC) configurations show higher cooling effectiveness compared to the single-wall pin-fin (PF and TF) designs and the triangular pin fin (TF and TFC) showed a higher heat transfer augmentation compared to the cylindrical pin fin (PF and PFC) design. Numerical study later confirmed that the triangular pin fin creates a pair of streamwise vortices that augments the local heat transfer. The presence of the pin fin in the double-wall configuration prevents the development of a strong crossflow that negatively affects the heat transfer of the impinging jet. In addition, the triangular pin fin not only prevents the strong crossflow but redirects the coolant in the lateral direction that eventually contributes to the formation of a counterrotating vortex pair in the streamwise direction and thus augments local heat transfer and improves overall cooling effectiveness. Pressure drop measurement showed that the full-length triangular pin fin has a higher-pressure loss but the partial-length pin fin can lower the pressure loss considerably without compromising additional cooling performance.

本文涉及矩形通道中四种针翅冷却结构的实验和数值传热分析。研究了两种设计概念，分别采用了两种不同的针翅形（圆柱和三角形）几何形状。第一种设计包括单壁针翅结构，其中冷却剂流过全长圆柱形（PF）和三角形针翅（TF）的阵列。第二种配置涉及双壁针翅式射流配置，其中冷却剂射流撞击到目标壁上，然后流过带有射流（PFC）的部分长度的圆柱形针状鳍片和带有射流的部分长度的三角形针状鳍片阵列（TFC）。红外热像仪用于测量目标表面的稳态壁温，以评估整体冷却效果$\varphi$。进行了瞬态传热实验，以根据瞬态壁温评估内部传热系数。结果发现，与单壁针翅片（PF和TF）设计相比，双壁针翅片（PFC和TFC）配置显示出更高的冷却效率，而三角形针翅片（TF和TFC）显示出更高的冷却效率。与圆柱形销状翅片（PF和PFC）设计相比，具有更高的传热效率。后来的数值研究证实，三角形的针形翅片会产生一对沿流向的涡流，从而增加了局部传热。双壁构造中的针状翅片的存在防止了强烈的错流的发展，该错流不利地影响了撞击射流的热传递。此外，三角形的针状鳍片不仅可以防止强力的横流，而且可以使冷却剂在横向方向上重新定向，从而最终有助于在气流方向上形成反向旋转的涡流对，从而增加了局部传热并提高了整体冷却效率。压降测量表明，全长三角形针状翅片具有较高的压力损失，而部分长度的针状翅片可在不损害附加冷却性能的情况下显着降低压力损失。