绕水翼空化流动速度分布的DPIV测量与分析

Digital Particle Image Velocimetry Measurement and Analysis of Velocity Distribution in Cavitating Flows Around a Hydrofoil

利用数字式粒子图像测速(DPIV)系统,对绕Hydronautics水翼流场的时均速度分布进行了测量。结果表明:随着空化数的降低,空化结构的发展决定了整个流场的速度分布;低速高脉动区域的范围基本上对应于空化区域;空化区域核心处的最低速度分布变得更为均匀,并在向下游移动的过程中影响范围逐渐变小;水翼后部主流区速度分布经历了一个均匀—震荡—逐渐均匀的发展过程;在超空化阶段,水翼吸力面前缘相对应的空化区域与主流区有相近的速度分布,而其它空化区域仍为低速区。

The time-averaged velocity distributions in flows around a Hydronautics foil were obtained by means of a digital particle image velocimetry （DPIV） system. The measured results show that velocity distribution in the whole flowing field depends on development of the cavitation structures with decreasing of the cavitation numbers; the high-fluctuating region with lower velocity corresponds to the cavitation area; the lowest velocity distribution in the cavity core behaves more evenly, and becomes smaller as moving downstream; the main-stream velocity distribution experiences such developing process as the even-the fluctuant-the even gradually behind the hydrofoil; the fluid velocity distribution in the cavitation region, corresponding to the front of the foil＇s suction surface, approaches that of the main stream region, and the fluid velocity distribution of the other cavitation region is lower, in the supprcavitation stage.