下平板滑移对后台阶流的影响

Effect of lower-wall slipping on a backward-facing step flow

采用混合有限分析解法对后台阶流在下平板滑移作用下的流动状况进行了数值模拟,并在与典型后台阶流进行比较的基础上分析了下平板滑移对流动结构所产生的影响。计算结果表明,这种情况下的后台阶流动涡漩结构更为复杂,流动区域内生成三个漩涡,两个小漩涡位于下部漩涡区,其长度主要随着下平板滑移速度的增大而减小;一个大漩涡位于上部漩涡区,其长度随着下平板滑移速度和雷诺数的增大而增大,但雷诺数的影响更为显著。

A numerical solution for a backwardfacing step flow(BSF) by the action of lowerwall slipping is simulated with the hybrid finite analysis method. Based on the comparison of the computed results between lowerwall slipping BSF and typical BSF,the flow configuration effected by lowerwall slipping is analyzed.The comparison displays that the lowerwall slipping BSF has more complicated vortex structure with three vortexes in its flow region.Two small vortexes locate the lower with their lengths decreasing mainly with the increase of lowerwall slipping speed; one large exists in the upper and it lengthens with the increase of both lowerwall slipping speed and the Reynolds number, but is more significantly affected by the Reynolds number.