A NUMERICAL-SIMULATION OF HYDRODYNAMIC-FORCES OF GROUND-EFFECT PROBLEM USING LAGRANGES EQUATION-OF-MOTION

On the basis of the potential flow theory, Lagrange's equation of moti on is used to study the unsteady ground-effect problem. The forces and moments acting on the moving body are solved in terms of the derivati ves of added masses in which the generalized Taylor's formulae are app lied. The singular integral equations used to solve the surface source intensities and their derivatives are regularized by the Gauss flux t heorem and are therefore amenable to the direct use of the Gaussian qu adrature formula. In illustration, the condition of a prolate spheroid moving in the fore-and-aft direction at constant speed past a flat gr ound with a protrusion is considered. The hydrodynamic forces and mome nts acting on the moving spheroid are investigated systematically by v arying the size of the protrusion and the cruising height of the spher oid. (C) 1998 John Wiley & Sons, Ltd.