多股自耦合射流相干流动和换热特性数值研究

采用数值模拟的方法对多股自耦合射流在相干条件下的流动和换热特性进行了研究.研究结果表明:三股自耦合射流都在出口附近耦合成一股射流向下游运动,两侧的射流受到中间一股射流的卷吸融合在一起,融合后仍然是一股沿中心线对称的自耦合射流.在短轴中心截面自耦合射流型面较宽,射流喷出后在下游的扩展角度大,而长轴中心截面射流的型面较窄,扩展角度较小.在冲击靶板上,整个冲击区域呈现出中心温度最低的近似圆形的对称性分布,对流换热系数曲线呈现出中心对称的波峰分布形状,表明自耦合射流驻点区换热最强.对流换热系数沿靶板不同方向的分布趋势基本保持一致.

Numerical study on the flow and heat transfer characteristics of coupled synthetic jets

Numerical study on the flow and heat transfer characteristics of coupled synthetic jets was carried out.The results show that: Near the slot exit,three synthetic jets couple to one jet and move downstream.Two synthetic jets on both sides are limited and rolled by the middle synthetic jet until they merge together into one centrosymmetric synthetic jet.The synthetic jet spreads rapidly along the minor axis direction of the orifice with bigger spread-angle;while along the major axis direction,the synthetic jet contracts firstly and then spreads slowly.At the target surface impinged by the synthetic jet,the temperature field is symmetric with the lowest filed in center.The heat transfer coefficients also take on the same trends with centrosymmetric waves,which means that the best cooled area is the stagnation.The distribution of heat transfer coefficients along different directions of the target surface is basically uniform.