Objectives To enhance the combat effectiveness of underwater weapons and improve firing accuracy, analysis is required of the high-speed oblique water-entry characteristics of truncated cone head twin vehicles in a parallel configuration.

Methods Using the CFD software Star - CCM+, this study applied the Realizable k - ε turbulence model to solve the Reynolds - averaged equations and integrated overlapping grid technology to accurately capture flow field characteristics. To track vacuum bubble evolution, the volume of fluid (VOF) method was combined with the Schnerr - Sauer vacuum bubble model. Finally, numerical simulations were performed on the high-speed oblique water-entry process of twin vehicles in a parallel configuration under different inclination angles and clearances. The variations in vehicle velocity and displacement, the distribution characteristics of pressure loads, and the evolution behavior of the cavity morphology were analyzed.

Results Numerical results show that parallel dual vehicles at 8°–18° exhibit a complete ricochet motion. As the attack angle increases, the ricochet phenomenon is delayed, along with increased vacuum bubble outer wall pressure and cavitation intensity. For the parallel arrangement of twin vehicles, at a clearance of 1.2D, significant fusion occurs in the cavities and wakes of twin vehicles. When the clearance increases to 3.2D, vacuum bubble evolution resembles that of a single vehicle, improving motion stability and intensifying the ricochet phenomenon.

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