Numerical investigation of the water entry of inclined cylinders using dynamic sliding mesh method

Abstract

There is a lack of considerations on water entry problems of inclined cylinders with the same mass, which is important to practical engineering problems such as hydrodynamic performance optimization. Therefore, this work focuses on the effects of diameter-length ratio and water entry angles on the hydrodynamic forces on cylinders with the same mass. A numerical model for the water entry of inclined cylinders is developed. A novel dynamic sliding mesh method is implemented in OpenFOAM based on the coupling of the sliding mesh and mesh morphing methods. A spring-like mesh motion strategy is proposed. The major advantages of this self-implemented mesh handling method are on accommodation of the large amplitude of the six degree-of-freedom motion of a cylinder (rigid body) and the preservation of the mesh non-orthogonality. By comparing with a laboratory study and another numerical simulation, the proposed numerical model shows a good consistency. The effects of the aforementioned parameters on the pressure forces and cylinders’ motions are investigated. A dimensional analysis is conducted to find the correlation between the maximum vertical pressure force and various parameters. An equation is proposed with a good agreement with the numerical results, which can provide references for practical water entry problems. The developed model can also be used in the simulations of more complicated water entry scenarios and ship hull slamming.