Underwater vehicles navigating through water generate accompanying nonlinear hydrodynamic phenomena around their structures, such as vortices and form distinct wake characteristics behind them which can be detected and exploited. Therefore, modifying the connecting surfaces between the main body and the tail appendages of underwater vehicles is significant for enhancing their performance. This study innovatively proposes a fillet-shaped control surface between the tail appendage and the hull body. A series of discussions were conducted to examine the changes in the turbulent kinetic energy of the wake behind the vehicle as the fill ratio of the fillet-shaped control surface, the navigation speed and the submersion depth vary. Thereby, the influence of the fillet-shaped control surface on the hydrodynamic performance of the underwater vehicle is revealed. The results indicate that adding a fillet-shaped control surface between the main body and the tail appendage alters the pressure distribution around the underwater vehicle, consequently affecting the turbulence intensity of the wake flow. Further research shows that the turbulent kinetic energy in the wake flow of the underwater vehicle decreases significantly by approximately 57% when the height of the fillet-shaped control surface is full of the original value. Additionally, the addition of the fillet-shaped control surface reduces vortex generation and the turbulence intensity of the wake. This study provides a novel approach for improving the flow field of underwater vehicles.
Bao et al. (Sun,) studied this question.