The effects of jet velocity ratio and skew angle were addressed . several co - rotating minute vortexes on the turbulence boundary layer would coalesce together that leaded to a big vortex . the effect of the big vortex was greater than a single minute one 单排多个同向射流与主流作用所产生的独立小涡旋将在流向下游发生合并,形成大涡旋,大涡旋对边界层的作用效果要强于单个独立小涡旋。