Viscous-flow calculations for KVLCC2 in deep and shallow water

In the SIMMAN 2008 workshop, the capability of CFD tools to predict the flow around manoeuvring ships has been investigated. It was decided to continue this effort but to extend the work to the flow around ships in shallow water. In this paper, CFD calculations for the KLVCC2 are presented. The aim of the study is to verify and validate the prediction of the influence of the water depth on the flow field and the forces and moments on the ship for a full-block hull form. An extensive numerical investigation has been conducted. For each water depth, several grid densities were used to investigate the discretisation error in the results. In general, the uncertainties were found to increase with increased flow complexity, i.e. for larger drift angles or yaw rates. A dependency of the uncertainty on the water depth was not found. The predicted resistance values were used to derive water-depth dependent form factors. Comparisons with resistance measurements and with an empirical formula given by Millward show good agreement for deep as well as for shallow water depths. The CFD results give insight into the forces and moments acting on the ship as a function of the drift angle, yaw rate and water depth. A clear dependence of the forces and moments on the water depth is found for steady drift conditions. For pure rotation, this dependence is much more complex and only develops fully for larger non-dimensional rotation rates. The paper shows that CFD is a useful tool when studying the flow around ships in restricted water depths