A POTENTIAL BASED PANEL METHOD FOR 2-D HYDROFOILS

A potential based panel method for the hydrodynamic analysis of 2-D hy drofoils moving beneath the free surface with constant speed without c onsidering cavitation is described. By applying Green's theorem and th e Green function method, an integral equation for the perturbation vel ocity potential is obtained under the potential flow theory. Dirichlet type boundary condition is used instead of Neumann type boundary cond ition. The 2-D hydrofoil is approximated by line panels which have con stant source strength and constant doublet strength distributions. The free surface condition is linearized and the method of images is used for satisfying this free surface condition. All the terms in fundamen tal solution (Green function) of perturbation potential are integrated over a line panel. Pressure distribution, lift, residual drag and fre e surface deformations are calculated for NACA4412, symmetric Joukowsk i and van de Vooren profile types of hydrofoil. The results of this me thod show good agreement with both experimental and numerical methods in the literature for the NACA4412 and symmetric Joukowski profile typ es. The lift and residual drag values of the van de Vooren profile are also presented. The effect of free surface is examined by a parametri c variation of Froude number and depth of submergence. (C) 1998 Elsevi er Science Ltd. All rights reserved.