TWO DIMENSIONAL ANALYSIS OF FLUID-STRUCTURE INTERACTION FOR RIGID BODIES SUBMERGED UNDER WATER USING BOUNDARY ELEMENTS

Abstract

This dissertation presents the two-dimensional analysis of fluid-structure interaction problems using the boundary element method. The focus is on the solution of the problem by boundary element analysis and their comparison with the corresponding solutions provided by the finite element method. The presentation has been organized in three chapters. The first chapter has three sections. The first of these intro-duces the general fluid-structure interaction problem and the concept of the added mass. The second section is devoted to review of the literature, while the third section provides an overview of the numeri-cal techniques available for the solution of engineering problems, high-lighting the advantages provided by the boundary element method. The second chapter presents the analysis for obtaining the added mass matrix, using the boundary element method. The governing equation namely the Laplace Equation has been derived using the Navier-Stokes Equation and the continuity equation. The method of weighted residuals has been adopted to develop the boundary element formulation. Finally, the third chapter presents the results and discussions Comparison of the results for pressure and added mass coefficients have been made with closed form solutions and those provided by the finite element method, wherever they are available. Also, included are three appendices. The approach for condensing a system of equations to involve only the quantities of interest is presented in Appendix-1. Appendix-2 gives a list of formulae used to obtain added mass for a few cases. Appendix-3 gives the computer program that was developed on the basis of the boundary element analysis.