Trim wedge optimization with viscous free surface computations

A procedure for automatic optimization of a ship hull and trim wedge is described, that is based on an evaluation of a series of hull form/trim wedge combinations. These evaluations are done with a RANS method that can accurately and efficiently compute the viscous flow for several transom flow regimes, ranging from completely dry to (partly) wetted. The object function is an approximation of the required power to maintain a given speed. Results obtained from several trim wedge optimizations are shown, computed and measured trends are compared and computed scale effects in those trends are discussed. For two examples, a considerable improvement of the object function can be obtained. At full scale, the improvement of the object function is stronger than at model scale.