Wave Run-up And Wave Interaction Numerical Analysis Of Multi-column Structure

With the depletion of land resources,people gradually turn their needs to the ocean.While exploiting oil and gas resources on the seabed,the complex and harsh marine environment in the deep sea poses severe challenges to the safety performance of various floating platforms,while using high-quality offshore wind energy resources,the ever-changing offshore environment also poses a challenge to the safety performance of fixed wind turbines.Whether it is a floating platform or fixed wind turbines,their main structure is a single column or a multi-column structure,in the complex marine environment,such structures can cause significant wave run-up and wave interaction problems between columns,it will lead to the loss of structural air gap and pose a greater threat to structural safety.The CFD method was used to simulate the wave run-up and wave interaction problems between columns in order to provide a certain reference for revealing the influence mechanism.Firstly,a numerical wave tank was built based on the CFD software Fluent.The wave making program is loaded at the inlet boundary of the water tank,the wave elimination program is loaded in the wave elimination area,and the free surface is tracked using the VOF method to realize the numerical generation of the second-order stokes wave.Through the comparison of numerical wave and theoretical wave under different mesh division schemes,the calculation accuracy and calculation time are comprehensively considered,and the most suitable mesh scheme is selected.In order to verify the rationality of the numerical method for studying the wave run-up problem,some experimental results of wave run-up along vertical cylinder in the literature were compared with the numerical results calculated my numerical water tank,the comparison results confirm the rationality of the numerical method.Secondly,the effect of wave parameters on wave run-up characteristics of a single column was studied in this numerical wave tank,the wave steepness parameter kA,the scattering parameter kR and the water depth parameter kd were considered respectively.Research results indicates: the change of wave steepness parameter will significantly affect the wave run-up value on the front surface of the column,large scattering parameters will change the distribution of run-up values around the column,when the water depth parameter is small,the run-up value of the front surface will increase significantly.After summarizing the calculation results,the wave run-up coefficient m is linearly fitted with kA and kRaccording to the velocity head theory,so that a linear relationship between m and kA,m and kR within a certain range are obtained.With reference to the theory of wave-flow interaction,a wind-wave-flow coupled numerical tank was built to study the effect of wind and flow on wave run-up characteristics of column.Studies have shown that the presence of wind and currents significantly enhance the wave run-up around the column and enhances the nonlinear characteristics.Based on the improved Jonswap spectrum,realize the numerical generation of random wave.Studying wave run-up characteristics of column under random wave conditions.Studies show that using large wave components in random wave sequences to describe wave climbs is more reasonable.Finally,the wave interference characteristics of the four-column structure were studied in the established numerical wave tank,mainly considering the influence of incident wave parameters and the wave incident angle.The mutual interaction mechanism of internal water between the columns is determined by the analysis of the interaction process of the waves between the columns under the 0° and 45° wave incidence conditions.At the same time,the force characteristics of the four-column structure under various conditions were studied,and the near-trapping phenomenon was motivated when the wave was incident at 45°.In this paper,starting from the study of wave run-up characteristics of a single cylinder,the incident wave parameters,wind-wave-flow coupling effect,and wave run-up characteristics under random wave conditions are fully considered.Based on this,the wave interaction characteristics of four columns are explored.Some innovative conclusions were obtained,I hope these conclusions could provide some theoretical references for the design of marine structures.