Investigation of three-dimensionality effects of aspect ratio on water impact of 3D objects using smoothed particle hydrodynamics method

Abstract

This article presents a study of 3D water entry problems by weakly compressible smoothed particles hydrodynamics (WCSPH) method. Water entry of prismatic wedges, circular cylinders and spherical bodies are presented. All cases are performed at a constant speed considering the effect of gravity. First-order density filter, turbulence modeling and a pressure filter are applied. Pressure distribution and free surface profiles are produced in all cases. For prismatic wedge water entry, computed results are compared against 2D BEM solution, but for circular cylinder water entries, the obtained results are compared against the VOF, analytical and experimental solutions. Furthermore, the obtained results for sphere water entry are compared against available experimental data. Favorable agreements are achieved in all the considered cases. It is demonstrated that the third dimension can affect the pressure distribution up to 50 % for the wedges and 40 % for the circular cylinders in the mid-length. Also, the spray height can be decreased nearly 30 % for a wedge and 50 % for a circular cylinder. Furthermore, the effect of deadrise angle of the wedge on the three-dimensionality effect is analyzed.