Numerical Simulation of Water Entry of Objects in 6DOF Motions

This paper presents the numerical solutions of water entry problems for three-dimensional (3D) shaped bodies entering into calm water with inclined angles. Hydrodynamic aspects of water entry are analyzed by investigating water entry problems of objects with inclined angles. The numerical method is based on the dual-time preconditioned Navier-Stokes (NS) equations solved with using multi-block and parallel computing to improve the computational productivity. In order to handle the motion of an object in 3D water entry problems, six degree-of-freedom (6DOF) rigid body motion model and a moving Chimera grid scheme are dynamically integrated into the NS solver. The Chimera domain decomposition scheme uses an overlapping, embedding, and a moving grid approach to facilitate the flow simulations of arbitrary translational and rotational complex geometries among various computational blocks. Solutions for free falling wedge and cylinders with inclined angles and flight simulation of a supercavitating water entry projectile are presented. The predicted kinematics and dynamics of the objects were analyzed and compared with experimental data.