Comparisons Between 2D+t Potential Flow Models and 3D RANS for Planing Hull Hydrodynamics

The flow generated by a wedge shaped hull in steady planing motion is simulated numerically by a 2D+t potential flow model and by a 3D RANS solver. A comparison between the two solutions is established in order to understand the role played by three-dimensional effects, neglected within the slender body assumption. The analysis is focused on the evaluation of the free surface shape and of the pressure field acting on the hull surface. It is shown that a good agreement is achieved in terms of the free surface profile, provided a correction is applied to the 2D+t solution to account for the rise up of the water in front of the hull. The comparison in terms of pressure distribution reveals important three-dimensional effects in the very fore part of the hull, in the region about the separation point and at the transom.