圆转矩形喷管射流掺混特性试验研究

本文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、窄对称面上射流的速度、雷诺剪应力、湍流强度，得到其沿径向和轴向的分布规律。发现在径向方向上，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。

Experimental Investigation of Mixing

In order to measure he flow field and mixing characteristics of the jet from rectangular nozzle,the single incline hot-wire was used in the experiments. The results showed that in the radial direction, the strongest mixing appears near the interface of ambient gas and jets, and caused the maximum value of Renaults shear stress in the same position, while the turbulent intensity has the largest value near jet axis. In the axis, Renaults shear Stress decreased lonely, while turbulent intensity increased a little, then decreased with the distance increase in axis direction.