圆转矩形喷管射流掺混特性试验

Experimental investigation of mixing characteristics of jet from circle-rectangular transition nozzle

采用热线风速仪对圆转矩形收敛喷管的射流流场与掺混特性进行了试验研究,测量了喷口下游不同截面上,射流宽、窄对称面上的速度、雷诺剪应力、湍流强度的分布规律.发现沿径向,雷诺剪应力先增大后减小,最大值出现在射流与外流的交界面附近,湍流强度则逐渐减小;在轴向上,雷诺剪应力在近喷口区存在小幅波动,而后逐渐减小,湍流度则先略有增大而后变化逐渐减慢.射流特性在宽对称面与窄对称面上的分布规律相同.

In order to measure the flow field and mixing characteristics of the jet from rectangular nozzle,the single incline hot-wire was used in the experiments.The results show that,the strongest mixing appears radially near the interface of ambient gas and jet,and causes the maximum value of Renaults shear stress in the same position,while the turbulent intensity decreases radially.Reynolds shear stress decreases axially,while turbulent intensity increases a little,and then decreases axially.