Time-domain Numerical Study on A Three Dimensional Body Undergoing Large-Amplitude Motions in Waves

摘要

Based on body nonlinear theory, the hydrodynamic problems of arnthree-dimensional body undergoing large amplitude motions arernstudied in the time domain. In the present method, the exact bodyrnboundary condition is satisfied on the instantaneous wetted surfacernwhile the free surface boundary condition is linearized. The initialboundaryrnvalue problem is formulated using a time-domain Greenrnfunction. A "Time-frequency Transform Method" is proposed torncalculate the convolution involving time-domain Green function.rnNumerical computations are first carried out for a submerged spherernundergoing forced motions. The results are compared with thernpublished solutions, which validate the numerical model. Furtherrncomputations are performed for a mooring JIP Spar in bichromaticrnwaves. The body nonlinear effects on the results are discussed byrncomparison with linear time-domain solutions.