Experimental and Numerical Study of the Cloud Cavitating Flow Around a Slender Cylinder With a Petals-Shaped Section

Three-dimensional flow structures of sheet-to-cloud transition have attracted a lot of attentions in the past years. Cloud cavitating flow around a slender cylinder with the petals shaped section was investigated by experimental and numerical methods. The experiment was performed in a launching system on the basis of the SHPB technology with a high-speed camera. The numerical method was established with large-eddy simulation (LES) and volume of fraction (VOF) approach. Numerical results agree well with experimental data. Interesting phenomena of three-dimensional evolution are observed, especially in which the U-type shedding of cavities are generated repeatedly in the channels along the inner region. Analysis of the unsteady evolution of cavitating flow is performed, and emphasis is placed on the study of the relationship between flow structures around the ridges and channels. Results demonstrate that the pressure gradient variation in the tangential direction of the cylinder is essential for the unsteady development of the cavity including re-entry jet and local shedding. Interactions between the cavity and vortex are also analyzed, which indicates that the U-type cavity/vortex shedding is jointly induced by the re-entry jet and tangential vortex.