中文摘要：

为了研究绕不同头型回转体的空穴发展特性，采用高速录像技术分别观察了绕平头和半锥角为45＆#176;的锥头回转体在不同空化数下的形态特征，应用粒子测速系统（PIV）测量了其速度、涡量及湍流脉动等分布情况。研究表明，相比于锥头回转体，同一空化数条件下，平头回转体的空穴最大尺度较大，且其随空化数的变化率亦较大；平头回转体空穴在发展的过程中表现为大尺度空泡团的融合、脱落及溃灭，表现较大的脉动，锥头回转体则为小尺度空穴的溃灭及再融合进而溃灭，空穴的脉动较小；空穴区域对应于低速高脉动区域；随着空化数的减小，速度分布趋于均匀，空穴内部流动脉动增强，高湍动能区域逐渐增大。

英文摘要：

A high-speed video camera was used to observe the process of cavity development,flow characteristics and effects of headforms around two axisymmetric bodies with blunt and 45＆#176; half cone angle shaped headforms re-spectively,with the circumstances of different cavitation numbers. A particle image velocimetry（PIV）system was employed to measure the velocity,vorticity and turbulent energy fields. The results show that at a given cavitation number,the maximum scale of the cavity around the blunt body is significantly bigger than that of the cone-shaped body. And as the cavitation number decreases,the cavities of the blunt body develop faster as compared with the cone-shaped body. It has been found that the process of cavity development around the blunt body represents a number of large cavity vortexes conjunct with each other,then they shed and disappear together with obvious un-steady characters,while there is a small scale cavity behaving around the cone-shaped body. In addition,from the flow field it appears that in the cavity area the flow speed is low and the instability is pronounced meanwhile the ve-locity distributing trends uniformly. What′s more,with the cavitation number decreasing,the fluctuations in the cavities become fairly pronounced which induces the turbulent instability and causes the area with high turbulent energy to spread and broaden.