Analysis of the influence of angle of attack on ventilated supercavitating flow in the bow rudder configuration

The bow rudder layout of high-speed supercavitating vehicles significantly influences the dynamics of ventilated supercavitation flow, exhibiting complex cavitation characteristics. To investigate the multiphase flow and hydrodynamic properties of the bow rudder layout under varying angles of attack, we developed an unsteady three-dimensional numerical method for high-speed ventilated supercavitating flow based on the inhomogeneous flow model. The effectiveness of this numerical method was rigorously validated against experimental data. The results indicate that the bow rudder induces the formation of concave supercavity cross sections. Compared to the condition at a 0° angle of attack, the angle of attack complicates the coupling relationship between the vehicle and the supercavity shape. The ventilated supercavitation flow, supercavity closure modes, and hydrodynamic forces associated with the bow rudder configuration are significantly influenced by the angle of attack. As the angle of attack increases, three distinct transitions in supercavity closure modes are observed, leading to notably different and complex variations in hydrodynamic characteristics. Furthermore, the impact of the bow rudder angle on supercavitating flow and hydrodynamic forces has been obtained and analyzed. It was found that the rudder angle induces a rotational deformation in the transverse section of the supercavity, improving the wetting conditions of the conical section and enhancing the hydrodynamic characteristics of the vehicle. Additionally, the hydrodynamic characteristics of the bow rudder under varying rudder angles and angles of attack, as well as their underlying generation mechanisms, were analyzed and elucidated.