Calculation of twodimensional nonlinear fluid flow resulting from largeamplitude forced heave motion of a ushaped cylinder in a free surface
Abstract
Progress in developing a tool to compute large amplitude ship motions is reported. In particular, a method to calculate transient twodimensional potential flow about a body moving in a free surface is described. The flow problem is formulated as an initialboundary value problem in which the velocity potential along the free surface and the positions of the moving boundaries are sought as solutions of a coupled system of differential equations. An implicit finitedifference method is used to advance the solution of the coupled system of equations in time. The auxiliary problem of computing the velocity potential inside the fluid region is solved by a method which is based on boundaryfitted coordinates and is directly extensible to threedimensional flows. Results from calculating the potential flow about a body in forced heave motion are presented. The hydrodynamic force on the body has been obtained and compared with the hydrodynamic force predicted from secondorder perturbation theory.
 Publication:

Final Report Naval Ship Research and Development Center
 Pub Date:
 December 1985
 Bibcode:
 1985nsrd.reptR....T
 Keywords:

 Boundary Value Problems;
 Fluid Flow;
 Nonlinearity;
 Ships;
 Two Dimensional Flow;
 Differential Equations;
 Finite Difference Theory;
 Hydrodynamic Equations;
 Perturbation Theory;
 Potential Flow;
 Surface Properties;
 Three Dimensional Flow;
 Fluid Mechanics and Heat Transfer