Dissipation in the gap resonance between two bodies

The energy dissipation in the fluid domain is evaluated by using CFD method when a resonance of wave elevations occurs in the gap between two bodies. The introduction of dissipation in the classical potential method permits to predict the wave elevation close to model tests. The estimation of associated dissipation coefficient is performed by the equivalence of dissipative force and friction forces on gap walls, and by the equivalence of energy dissipation rate and the power consumed on the gap free surface by the dissipation force. It is shown that the friction on gap walls represents only 1/6 of total dissipation, and that the introduction of full dissipation in the domain around the gap gives correct predictions.