A rectangular microchannel with truncated and offset pin-fins is designed, and investigated using numerical simulation. The width (W_c) and height (H_c) of a single smooth microchannel are 0.1 mm and 0.2 mm, respectively. The pin-fin length, width and height (H_r) are 0.06 mm, 0.03 mm and 0–0.2 mm, respectively. The offset value (W_r) of two adjacent pin-fins in width direction of microchannel ranges from 0 to 0.07 mm. The effects of relative height (H_rc = H_r/H_c) and relative offset value (W_rc = W_r/W_c) on hydrothermal performance and entropy generation are analyzed. Results show that increasing pin-fin height usually results in both higher thermal enhancement and flow resistance. Increasing pin-fin offset value properly can enhance heat transfer, but extremely larger offset value leads to decrease of thermal enhancement. The microchannel with H_rc = 0.75 and W_rc = 0.6 yields the maximum overall thermal performance factor of 1.43. The minimum augmentation entropy generation number of 0.31 is obtained in microchannel with H_rc = 0.75 and W_rc = 0.4. From comparison of variable and constant fluid properties, variable fluid properties significantly affect flow and heat transfer performance. Particularly, fluid viscosity plays a key role in fluid properties while others have unobvious effect.

设计了具有截短且偏移的引脚鳍的矩形微通道，并使用数值模拟对其进行了研究。单个平滑微通道的宽度（W _c）和高度（H _c）分别为0.1 mm和0.2 mm。针鳍的长度，宽度和高度（H _r）分别为0.06 mm，0.03 mm和0-0.2 mm。两个相邻的针状鳍片在微通道的宽度方向上的偏移值（W _r）在0至0.07mm的范围内。相对高度（H _rc  =  H _r / H _c）和相对偏移值（W _rc  =  W _{r）的影响}/ W _c）对水热性能和熵产生的影响。结果表明，增大针鳍高度通常会导致更高的热增强和流阻。适当增加针脚-鳍片偏移值可以增强传热，但是极大的偏移值会导致热量增强降低。H _rc  = 0.75和W _rc  = 0.6的微通道产生的最大总热性能系数为1.43。在H _rc  = 0.75和W _rc的微通道中获得的最小扩充熵生成数为0.31 = 0.4。通过比较可变流体特性和恒定流体特性，可变流体特性会显着影响流动和传热性能。特别地，流体粘度在流体性质中起关键作用，而其他则没有明显的作用。