中文摘要：

利用二维粒子图像测速技术（PIV）对旋转水射流喷嘴内部流场进行了测量,将喷嘴入流条件分为入流流量比（切向流量与轴向流量之比）以及入流总流量两个因素,分析了两者对喷嘴出口旋流结构、切向速度分布以及喷嘴出口旋流数的影响。实验结果表明,入流流量比对喷嘴出口的切向速度大小及其径向分布都有影响,而入流总流量只影响其大小;入流流量比和入流总流量的增加均可使喷嘴出口的旋转流动增强,但只有入流流量比的增加可使喷嘴出口旋流数增加,而旋流数是喷嘴加旋效果的检验标准。

英文摘要：

An experimental system for the swirling water jet nozzle is established to investigate the swirling characteristics of the nozzle flow,and the velocity field in the nozzle is measured with a two-dimensional particle image velocimetry（PIV） system.An quantitative analysis on the internal flow structure,tangential velocity distribution and swirling intensity shows that,among the two parameters,i.e.the flow rate ratio（tangential inflow vs.axial inflow） and the total flow rate of the nozzle inlet condition,the former determines the magnitude and distribution of the tangential velocity,and the latter determines the magnitude only.The tangential velocity can be enhanced by increasing either of the two inlet parameters,but only the flow rate ratio makes contribution to the swirling number that characterizes the nozzle outlet swirling and hence dominates the water flow jetted from the nozzle.