Interaction Between Multi-directional Wave And Structure

Based on the velocity potential theory,the previous research on the interaction of wave with objects is mainly about the linear frequency domain,frequency domain second order and linear time domain,and most of then are limited to regular waves,the corresponding experiments also uses regular waves or unidireetional irregular waves.However,in the reality wave is random irregular wave,and the space energy is distributed in a wide frequency range.Therefore,it is of practical significance to study the generation of multi.directional waves for simulating the real marine environment.In this paper,we use the time.domain second.order potential flow theory to solve the velocity field by using the Desingularized Boundary Integral Equation Method.Finally,the interaction of multi.directional wave with submenged and surface piericing structure is studied.Details are as follows:(1)The accuracy of the Desiularized Boundary Integral Equation Method(DBIEM)is analyzed.Taking the three.dimensional uniform flow over a sphere as an example,the key parameters of the singularity are analyzed in detail,and the numerical results are compared with the analytical solutions in the related literature.At the same time,the range of the singular parameters satisfying the accuracy of the flow around the sphere is given.The conclusion can lead to the study of the DBIEM in the field of ship and ocean engineering hydrodynamics.(2)A time.domain method is presented to simulate 3D wave.body interaction and the convergence of the key control parameters for the singular boundary element is studied for the wave.body interaction problem.In this paper,the implementation process of DBIEM method is described in detail,followed by the convergence analysis of its key control parameters,and the eucuracy has been identified by comparise with the published results.Finally,the second.order diffraction problem of a vertical cylinder cylindrical is used to verify the possibility the model to simulate the interaction between water wave and simple shape structure.(3)The DBIEM method is used to solve the mathematical model.The numerical simulation of unilateral and multi.directional nonlinear wave diffraction is carried out and the results of single and multi.directional numerical simulation are compared.The simulation results show that the multi.directional wave has a significant enhancement effect on the second.order wave force compared with the unidirectional wave.