Numerical investigation into water entry problems of a flat plate with air pockets

Abstract

Computational Fluid Dynamics (CFD) investigations into water entry problems of a rigid flat plate with air pockets were systematically conducted. The Volume of Fluid (VOF) model was utilised to capture localised slamming phenomena that occur during, and post-impact events. The model's geometry was modified to include a pocket on the slamming impact surface to investigate the effect of air entrapment on the magnitude and distribution of slamming forces and pressures. A parametric study was conducted on the geometric parameters of the modelled pocket by altering its area, depth, and volume to examine the response of slamming force and pressure loading under several impact velocities. The numerical results of slamming forces and pressures were in good agreement with experimental drop test measurements (with relative error of -6% and 7% for the magnitude of slamming force and pressure, respectively). The numerical results proved that the peak pressure is proportional to the magnitude of impact velocity squared ($p_{max}\propto v^2$).