旋转水射流冲击压强的实验分析

利用测压排摄像自动读数法，测量了水垫式旋转磨料射流喷嘴所产生旋转射流的冲击压强。该方法对测压排内水面标志物进行连续摄像，然后利用计算机程序对所摄图像自动读数，可以用较低的成本较好地实现非恒定压强的测量。实验结果表明，对于水垫式旋转磨料射流喷嘴产生的旋转射流，切向入流与轴向入流流量之比（流量比）及之和（总流量）是其冲击压强的控制性因素，前者控制其分布和大小，后者只对其大小有影响；各股切向入流的流量不均匀性对射流冲击压强时均值的影响很小；冲击压强脉动强度随着作用位置到射流中心距离的增大而减小。

EXPERIMENTAL STUDY ON THE IMPACT PRESSURE OF SWIRLING WATER JETS

The impact pressure of swirling jets,produced by water-cushion swirling abrasive jet nozzle,was measured by continuous shooting images of the symbol in the piezometer tubes.Based on computer image processing technology,the development of dynamic impact pressure under different inflow conditions was obtained automatically.It is shown that the flow rate ratio of tangential inflow to axial inflow and total flow rate were the control factors of the impact pressure,with the former determining the distribution and scale of the impact pressure,while the latter determining the scale only.Moreover,the influence of flow rate alteration of the tangential inflows from four directions upon the time-averaged pressure was rather little,and the fluctuation of the dynamic pressure became small as the distance between the gaging point and jet-core increased.