The features of flow fluid and convective heat transfer have been investigated numerically in a rotating rectangular U-shaped microchannel for various aspect ratios (AR). Pure water is used as working fluid and 3D steady simulations are performed for Reynolds number of 400. The effects of aspect ratio (AR = 0.25–4), slip/no-slip conditions, rotational speeds in the range of 0–300 rad/s on the velocity profiles/contours, heat transfer, pressure drop, Nusselt number, and thermal performance coefficient are studied. The results show that an increase in AR (for AR>1) or a decrease in AR (for AR<1) provided an increase in pressure drop and heat transfer. Besides, contrary to hydrophilic microchannel, the heat transfer and pressure drop decrease in microchannel with the hydrophobic surfaces for all ARs considered. In addition, the thermal performance coefficient (E) is used as a balance between heat transfer augmentation and the power consumed. It is found that the E is higher for microchannel with hydrophobic surface than that of with hydrophilic one for all ARs examined. Moreover, the rotating microchannel is more efficient in respect to heat transfer enhancement than that of the stationary case, especially at AR = 1. Moreover, the results for two thermal boundary conditions of constant heat transfer and constant wall temperature conditions are compared at AR = 1 and it is found that the total Nusselt number is higher for constant wall temperature case than that of constant heat flux case in rotating microchannel while it is contrary in stationary one.

已经对不同纵横比 ( AR )的旋转矩形 U 形微通道中的流动流体和对流传热的特征进行了数值研究。使用纯水作为工作流体，并对雷诺数为 400 进行 3D 稳态模拟。纵横比 ( AR  = 0.25–4)、滑动/无滑动条件、0–300 rad/范围内的转速的影响s 对速度分布/轮廓、传热、压降、努塞尔数和热性能系数进行了研究。结果表明，AR增加（对于AR >1）或AR减少（对于AR<1) 增加了压降和传热。此外，与亲水性微通道相反，对于所有考虑的AR，具有疏水表面的微通道中的传热和压降降低。此外，热性能系数 ( E ) 用作传热增强和消耗的功率之间的平衡。发现对于所有检测的AR，具有疏水表面的微通道的E高于具有亲水表面的微通道。此外，旋转微通道在传热增强方面比固定情况更有效，尤其是在AR = 1。此外，在AR  = 1时比较了恒定传热和恒定壁温条件的两种热边界条件的结果，发现恒定壁温情况下的总努塞尔数高于恒定热通量情况下的总努塞尔数在旋转微通道中，而在静止微通道中则相反。