Research on the pitching hydrodynamic performance of pump-jet propelled submersible

Most of the current research in the world on the dynamical characteristics of pump-jet propelled submersibles has focused on the dynamic response of non-vector propulsion. However, the dynamics characteristics of water jet vector propulsion by external bypass excitation have been neglected. Therefore, this paper explores the variable vector deflection angle-controlled pitching motion in the vertical plane of the submersible and the isokinetic constant linear pitching motion water motion. ANSYS software is used to perform numerical calculations to investigate the changes of drag and Lifting force with velocity under different navigation states. Conclusion: In the process of surfacing, the change trend of Lifting force and drag is the same: when adjusting the navigation deflection angle, it increases rapidly, and then when floating in a constant straight line, it gradually decreases, and finally, the decrease rate tends to level off; when the elevation angle increases, the change amplitude of drag and Lifting force increases. During the dive, the drag force decreases and the Lifting force increases, gradually, the rate of decrease of drag force and the rate of increase of Lifting force become smaller; when the pitch angle increases, the Lifting force decreases rapidly and the decrease of drag force becomes larger.