Wave resistance of a hovercraft moving in water with nonrigid bottom

Surface waves generated by a moving ship in water of finite depth are affected by the rheological properties of the movable bottom. The aim of this work is to evaluate the wave resistance exerted on a hovercraft modeled as a two-dimensional pressure distribution moving on the free surface of water with nonrigid bottom. Analysis of three-dimensional flows in two-fluid layers of finite depths is performed by assuming an inviscid upper layer (water) and a viscous lower layer (nonrigid bottom). Numerical calculations show that the maximum wave resistance occurs in the vicinity of the critical Froude number F=1. This maximum value decreases as the muddy bottom becomes less rigid.