基于Micro-PIV的流体绕流顺排微柱群流动特性分析OA

To clarify the flow characteristics of fluid moving around inline microcylinder arrays in mi-crochannels,the effects of Reynolds number(Re)and lateral cylinder spacing(normalized by cylinder diameter D)on time-averaged streamlines,vortex structures,vorticity,and dimensionless vortex length were investigated.A parallel array of micro-pillar was studied by Micro-PIV(microscopic parti-cle image velocimetry).By varying the spacing and Re,flow field data in the cylinder wake region were observed and collected under various conditions.The data were subsequently processed using flow field visualization and quantitative analysis techniques.The results indicate that the generation and shedding of vortices around microcylinder arrays at the microscale exhibit significant hysteresis com-pared to those at the macroscale.As Re increases,the size of vortices—both in terms of length and width—grows,the vorticity region extends downstream,and the dimensionless vortex length increases accordingly.When the spacing is 2.5D,increasing Re causes the vortex regions of the upstream and downstream cylinders to merge,forming a continuous vortex street.At smaller spacing,the downstream cylinders suppress vortiex formation on the upstream cylinders,whereas at larger spacing,multiple vor-tex intersections points emerge within the wake vortex structure.In conclusion,both Re and cylinder spacing jointly determine the flow field structure of fluid flowing around inline microcylinder arrays in microchannels.Re primarily influences the scale and dimensionless length of vortices,while spacing governs the interaction between vortices.These findings provide a scientific basis for flow field control and regulation in microfluidic devices.