Numerical simulation of water entry of a wedge using a modified ghost-cell immersed boundary method

The hydrodynamic problems of water entry of a wedge are investigated by a modified ghost-cell immersed boundary method. The modifications correspond to a newly proposed scheme for dealing with fluid-body interaction, and incorporation of CIP (Constraint Interpolation Profile) method and THINC/SW (Tangent of Hyperbola for Interface Capturing with Slope Weighting) method. The modified ghost-cell immersed boundary method uses a compact interpolation structure and gives the fluid properties to the ghost cell to achieve a more accurate treatment of fluid-body interaction. It can preserve the sharpness of the immersed boundary. To validate the new method, simulations of water entry of symmetric and asymmetric wedges in a single degree of freedom and water entry of an asymmetric wedge in three degrees of freedom are carried out, respectively. The variations of pressure, vertical velocity, vertical acceleration, angular displacement, and angular acceleration against time are focused on. The evolution of the free surface and velocity distributions of fluid is also analyzed. The results of numerical simulations are compared with available experimental results and fairly good agreement is obtained, which indicates that the present model is reliable.