Numerical simulation on the high-speed oblique water entry of twin vehicles in parallel configuration

To enhance the combat effectiveness of underwater weapons and improve firing accuracy, this study analyzes the high-speed oblique water-entry characteristics of twin vehicles with truncated cone heads in a parallel configuration.

Using the CFD software STAR-CCM+, the Realizable k–ε turbulence model was applied to solve the Reynolds-averaged equations. Overlapping grid technology was integrated to accurately capture the flow field characteristics. To track the evolution of vacuum bubbles, the volume of fluid (VOF) method was combined with the Schnerr–Sauer vacuum bubble model. Finally, numerical simulations were conducted to analyze the high-speed oblique water-entry process of twin vehicles in a parallel configuration under varying inclination angles and clearances. The study examined changes in vehicle velocity and displacement, pressure load distribution, and the evolution of the cavity morphology.

Numerical results indicate that parallel dual vehicles, when entering at attack angles between 8° and 18°, exhibit a complete ricochet motion. As the attack angle increases, the ricochet phenomenon is delayed, accompanied by higher pressure on the outer wall of the vacuum bubble and increased cavitation intensity. For twin vehicles in a parallel configuration, a clearance of 1.2D leads to significant fusion of the cavities and wakes of twin vehicles. When the clearance is increased to 3.2D, the vacuum bubble evolution becomes similar to that of a single vehicle, resulting in improved motion stability and a more pronounced ricochet phenomenon.

When twin vehicles enter water at high speeds in different configurations, the flow field and vacuum bubble morphology vary accordingly. The findings provide theoretical support and practical references for the design and application of supercavitating vehicles.