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利用实验方法研究了粗糙度对矩形截面微管道内液体流动阻力特性的影响,采用微观粒子图像测速技术测量了粗糙微管道内的流场结构.实验结果表明:在层流状态下,3%—7%的相对粗糙度可以导致微管道内流动阻力的明显增加,在粗糙单元附近形成的压差阻力是导致流动阻力增加的主要原因.粗糙单元还会引起微管道内的流动失稳,导致粗糙微管道内层流向湍流的转捩提前.
The effect of roughness on the liquid flow resistance in a microchannel with a rectangular cross section was studied by means of experimental methods, and the flow field structure in the rough microchannel was measured by the microscopic particle image velocimetry technique. The experimental results show that under the condition of laminar flow, The relative roughness of 7% can lead to a significant increase of flow resistance in the microchannel, and the pressure drop resistance formed near the coarse cells is the main reason leading to the increase of the flow resistance.Rough cells also cause the flow instability in the microchannel, leading to roughness Micro-pipe inner turbulent flow to the transition in advance.