A Numerical Way for a Stepped Planing Hull Design and Optimization

Stepped planing hulls enable the feasibility of running at a relatively low drag-lift ratio by means of achieving more optimal trim angle at high speeds than a similar non-stepped hull. Furthermore, stepped planing hulls ensure good dynamic stability and seakeeping qualities at high speeds. However, there is no precise method to analyze these hulls over the full range of operating speeds. For the above-mentioned reason, in this study, a CFD-based design was presented, starting from a non-stepped hull configuration, a multiple step solution was developed and an optimization of the unwetted aft body area behind the steps was performed. The goal of the optimization is the drag reduction and a dynamic stability. The CFD results were compared with the well-known empirical approach and a novel 2D+T analytical method.