Study of Characteristics of Inception Cavitating Flows around an Axisymmetric Blunt Body at Different Angles of Attack

The inception cavitating flows around an axisymmetric blunt body at different angles of attack are simulated to investigate the influence of near-wall flow structure on the characteristics of inception cavitation. The large eddy simulation (LES) method coupled with the Zwart cavitation model is applied based on the homogeneous flow model in the simulation of inception cavitation. The results show that the LES method gives good predictions of the incipient cavity shape and its time-evolution process. The inci-pient cavities exhibit irregularly bubble structures and are asymmetrically distributed in the separation vortex area at the shoulder of axisymmetric blunt body. As the angle of attack increases, the distribution area of incipient cavities in the incident flow region gradually decreases but increases in the backflow region. The distribution of incipient cavities is closely related to the time-averaged separation vortex structure. The vortex scale in the incident flow gradually decreases and tends to be close to the head and wall of axisymmetric blunt body. However, the separation vortex scale of the backflow gradually increases with the increase in the angle of attack. Especially for the larger angle of attack, a secondary separation phenomenon occurs near the reattachment point of the backflow, which induces the formation of inception cavitation. © 2020, Editorial Board of Acta Armamentarii. All right reserved.