Flow characteristics and heat transfer performance in the circular and annular microchannels with dimples/protrusions are studied numerically. The effects of Reynolds number (Re), dimple/protrusion size, combinations of dimples or protrusions, and arrangement pattern are examined. The results show that in circular microchannels, dimple cases show the poor heat transfer capacity and the staggered dimple case provides no significant difference. The aligned protrusion cases provide excellent heat transfer performance, which is further improved with the increase in protrusion size or Re, and the staggered protrusion case shows the worse heat transfer performance. In annular microchannels, the outer protrusion shows the better heat transfer effect superior to the inner protrusion. In protrusion microchannel, it will be helpful in avoiding the excessive additional flow resistance when dimples are fixed on the opposite wall. The arrangement has no significant effect on the heat transfer and friction characteristic, and the flow separation on the dimple (protrusion) side is suppressed when the protrusion (dimple) is fixed on the opposite wall. From the view point of energy saving, in circular microchannels, the protrusion cases provide the high effectiveness, and the staggered case possesses the lower effectiveness especially in the protrusion case.

对具有凹痕/凸起的圆形和环形微通道中的流动特性和传热性能进行了数值研究。研究了雷诺数（Re），凹痕/突起尺寸，凹痕或突起的组合以及排列方式的影响。结果表明，在圆形微通道中，酒窝情况显示出较差的传热能力，而交错酒窝情况则没有显着差异。对齐的突起盒提供出色的传热性能，随着突起尺寸或Re，交错的突出情况显示出较差的传热性能。在环形微通道中，外突出部显示出比内突出部更好的传热效果。在突起微通道中，当将凹窝固定在相对的壁上时，有助于避免过多的额外流动阻力。该布置对传热和摩擦特性没有显着影响，并且当将突起（凹窝）固定在相对的壁上时，抑制了在凹窝（突起）侧的流动分离。从节能的角度来看，在圆形微通道中，突出壳体提供较高的效率，而交错壳体的效率较低，特别是在突出壳体中。