Nonlinear Air Gap Prediction Analysis for Semi-Submersible Platform
In order to study the nonlinear characteristics of the air gap response of semi-submersible platforms and to guide the structural design of the platforms,the numerical prediction method and characteristics of the air gap nonlinear response of semi-submersible platforms are studied.Based on the accurate prediction of the vertical motion at specific positions of semi-submersible platforms using nonlinear numerical methods,a nonlinear component estimation method of the air gap response is proposed to obtain the air gap and wave elevation response at typical positions,and compared and analyzed with the results of model tests.The study shows that the nonlinear effect has a significant effect on the extreme values of air gap and wave elevation,and the linear analysis results obviously underestimate the wave surface rise response;the estimation results of the wave surface elevation response taking into account the nonlinear effect have a significant improvement,the estimation results of the air gap response agree well with the experimental results,and the estimation results of the wave elevation response also have some improvement effect,and can more accurately characterize the temporal history and spectral properties of nonlinear waves.
semi-submersible platformnumerical predictionwave elevationnonlinearityair gap response