Design And Application Of An Intelligent Suppression Device For Vortex Induced Vibration Of Marine Riser

With the development of offshore oil exploration,offshore riser systems will face more severe environmental loads.The suppression of vortex-induced vibration(VIV)has become a challenging problem for long and thin pipe structures in marine environment.Several types of VIV suppressor devices have been developed in the project,such as splitter plates,spiral strays,and fairing.However,under complex sea conditions,the traditional suppression devices have poor adaptability and lack of flexible adjustment ability.Based on RBF neural network combining with artificial contemplating the intelligent optimization algorithm is a fairing section shape optimization method is proposed,by using the intelligent optimization algorithm designed a deformable vortex-induced suppression device,the structure of the research and application of the riser system device configuration optimization problem,the relevant conclusion is available for suppression device in practical engineering design and installation of configuration provides certain reference.It is of great significance to the exploitation of marine oil and gas resources.Firstly,the classical two-dimensional cylinder vortex-induced vibration model is numerically simulated to verify the correctness of the CFD model.The optimization design of the fairing section shape was studied.The fairing section shape was constructed by quadratic Bessel curve,and parametric modeling was carried out.The numerical database of vortex induced vibration response of the fairing model under different sea conditions was established by co-simulation with COMSOL Multiphysics and MATLAB.The BP neural network and RBF neural network are used to forecast the training sample data and test sample data in the database respectively,and the optimal data-driven model is obtained by comparison.Based on the artificial fish swarm intelligent optimization algorithm,the shape of the fairing section was optimized by taking the data-driven model as the fitness function and the cross-current amplitude as the optimization objective.The corresponding fairing model with the optimal shape was obtained,and the optimized model was verified by CFD simulation and experiment respectively.Based on this method,an intelligent deformable vortex induced suppression device for engineering application is designed,and the deformation control strategy is proposed.This paper studies the application of suppressor in riser system and the optimization of installation and configuration of suppressor in riser system based on evolutionary theory.The results show that:(1)the RBF neural network has higher prediction accuracy than BP neural network,the fairing resulting from the combination of artificial fish algorithm is optimized model has good water dynamics,significantly reduces the cross flow to also reduce the amplitude of the drag coefficient,and by using CFD simulation and experiment show that this optimization method has better feasibility.(2)the design of intelligent deformable suppression device can achieve fairing with four modules,the deformation of two kinds of sea condition,for example,when the velocity changes,fairing suppression device control module control driver module for parameterized action,implement adaptive regulation suppression device,the final deformation to the ideal fairing section shape.(3)The optimization method was applied to the structural configuration optimization problem of the riser system with equality constraints and inequality constraints respectively,and the VORF of the riser system was significantly reduced.The results show that the proposed method can accurately and effectively optimize the configuration design of the riser suppression device.