Numerical investigation of bottom slamming using one and two way coupled methods of S175 hull

Abstract

Numerical simulations of bottom slamming are conducted for a S175 container ship hull using two-phase computational fluid dynamics (CFD) and potential flow solvers. Suitable combinations of these two different models are used for two different coupling strategies named one and two way coupling methods. Various parameters such as the incident wave steepness, wavelength and the forward speed (specified using the Froude number) in a head sea over a range are considered to investigate the slamming phenomenon based on the one way and the two way coupling methods. The overall analysis shows that for most of the cases, the prediction of the bottom slamming pressure from the one-way coupling method maintains a nearly steady difference with respect to that of the two way coupling method over the range of the input parameters and thus forms basis for a new empirical formulation to estimate the peak slamming pressure for a range forward speeds. The performance of this empirical formula is qualitatively discussed with respect to the prediction from the two way coupling method. It is observed that the derived analytical formulation gives reliable results and may be used for efficient estimation of bow slamming pressures at a relatively low computational cost.