WaveMaking In Time Domain For MultiHull Ships And Eulerian Equation Solution For Wave Body Interaction

A method of threedimensionaltime domain Green function satisfying linearconditions at free surface and body surface boundary was employed to analyze the waveresistance and wave profile of a displacement multihullship. The wave profile inducedby a moving time domain point source was compared with those by a Havelock source,and satisfactory results were obtained. The panel method based on the time domain sourcedistribution on the ship mean wetted hull surface was used to perform the wave makingcomputations for monohullships, catamaran and trimaran. Reasonable results were alsoobtained. Using the numerical method the wave profile simulations of multihullships fora given Froude number were conducted.The wave making of the hydrofoil is represented by the lifting line. The ship wavemaking incorporated with the hydrofoil is computed by 3DGreen function method intime domain. Wigley hull form with hydrofoil is employed as numerical example for thecomputation of monohullship and catamaran. Some computed results are presented. TheSeries 60 hull form is also used as numerical example and the computed results arecompared with published data. The ship wave making on the free surface is simulated intime domain.In the time domain analysis for the interaction of wave and floating body, anumerical scheme with time domain Green function panel method is developed and somerelative computations are carried out for a floating hemisphere. Good agreements havebeen obtained by comparing with others. Rankine source panel method is used for thememory function computation of hemisphere in surge and heave, respectively and theefficiency of the computational method is verified. The finite element method isdeveloped to compute the time domain radiation force of Wigley (3012) hull form in surge, heave and pitch motions. The computed results have been compared with those by timedomain Green function method and the satisfied agreements are also obtained.A wavebodyinteraction computation scheme, based on Euler's equation in the idealfluid, is formulated by the finite element method (FEM). The linear free surface boundarycondition is used. The unsteady Euler's equation is solved by the fraction step method andthe time step marching integration approach is employed to deal with the pressure Poissonequation, velocity equations and the wave motion on the free surface, independently. Toverify the present method a floating hemisphere oscillating on the free surface isintroduced for a numerical computation example. The computed results have beencompared with those by different theoretical methods.