Kangping Liao

Corrected First-Order Derivative ISPH in Water Wave Simulations

The smoothed particle hydrodynamics (SPH) method is a meshless numerical modeling technique. It has been applied in many different research fields in coastal engineering. Due to the drawback of its kernel approximation, however, the accuracy of SPH simulation results still needs to be improved in the prediction of violent wave impact. This paper compares several different forms of correction on the first-order derivative of ISPH formulation aiming to find one optimum kernel approximation. Based on four benchmark case analysis, we explored different kernel corrections and compared their accuracies. Furthermore, we applied them to one solitary wave and two dam-break flows with violent wave impact. The recommended method has been found to achieve much more promising results as compared with experimental data and other numerical approaches.

CFD Simulation of Flexible Ship in Regular Head Waves

The ship springing is continuous vibration of the hull girder due to encountered wave excitation, which is considered as a typical fluid-structure interaction (FSI) problem. In this study, a CFD approach is proposed for modeling ship springing induced by large amplitude regular waves. In the CFD model, nonlinear free surface flows are solved by a finite difference method based on CIP (Constraint Interpolation Profile) method. Flexible structure is calculated using one dimensional finite element method by idealizing the ship structure as a beam. A volume weighted method, which is based on IB (Immersed Boundary) method, is applied to couple the FDM and the FEM. The proposed numerical model is validated against an experiment on a flexible barge in regular waves. Discussions are made on the numerical results.Copyright

VIV simulation of 2-D deformable cylinder using coupled FDM/FEM method

In this work a coupled finite difference method and finite element method (FDM/FEM) is developed for numerical simulation of vortex induced vibration (VIV) phenomenon with an elastically deformable circular cylinder. The algorithm is based on a FDM with CIP (Constraint Interpolation Profile) method to fluid dynamics and a FEM to solve structural dynamics. Coupling between FDM and FEM is realized by BGS (Block Gauss-Seidel) procedure. IB (Immersed Boundary) method is applied for data transferring on the interface between fluid and structure. In this paper, numerical simulations of a 2-D circular cylinder at low Reynolds number are carried out. The effect of stiffness of the cylinder shell on the vortex shedding is investigated.Copyright