Impact Load Characteristics of Large-Scale Trans-Medium Vehicles during High-Speed Oblique Water Entry

Abstract

To investigate the impact load characteristics of large-scale trans-medium vehicles during high-speed oblique water entry, a three-dimensional unsteady numerical calculation model of high-speed oblique water entry of the trans-medium vehicles was established based on the volume of fluid (VOF) multiphase flow model and the S-DOF rigid body motion mode. The calculation accuracy of the numerical calculation model was checked and verified by using the free motion test data of the slender objects during high-speed water entry, and the impact load characteristics of the vehicles with flat heads and conical heads during high-speed oblique water entry were compared. The results show that the occurrence time of the maximum axial and longitudinal impact loads of the vehicle with a conical head is almost synchronous, while the maximum axial impact load of the vehicle with a flat head is significantly delayed compared with the longitudinal load. For the maximum impact load, the axial impact load of the vehicle with a flat head is greater than its longitudinal impact load, while the axial and longitudinal impact loads of the vehicle with a conical head are almost the same. Compared to that of the vehicle with a flat head, the axial impact load of the vehicle with a conical head is significantly reduced, and the maximum peak value is about 1/3 of that of the vehicle with a flat head when the water entry angle is 45°.

Keywords

• trans-media vehicle
• oblique water entry
• impact load
• multiphase flow