Research On Truncation Of Mooring System On SPAR Platform Based On NSGA-?

With the pace of ocean development gradually into the deep-sea waters,due to its good job performance and powerful features,SPAR was regarded as the next generation platform,which is used for deep-sea oil and gas production and development.At present,domestic and foreign scholars are also studying this kind of platform.In this paper,SPAR platform and its mooring system are taken as the carrier.First,hydrodynamic analysis,as the basis of analysis of motion response,is carried out in the frequency domain,then use the time domain analysis software AQWA to calculate the static characteristics and time domain response of the SPAR platform,laying the foundation for the next truncated design.In the equivalent water depth truncation design,using NSGA-? optimization algorithm for truncation design based on static characteristic similarity,the platform motion and force of the mooring system of 2000 meters depth are simulated with the truncation design of 700 meters.Optimizing mooring line length,diameter,EA and other related parameters,and a 1:70 scale was used to conduct model test.The model tests include free decay test,RAO test and irregular wave model test of SPAR platform.Based on the data obtained from the actual model test,at the same time the accuracy of the numerical calculation is verified.Finally,according to the difference between the two groups of data,numerical reconstruction and numerical extrapolation are carried out to obtain the final result.Truncation design is a very important part of the experiment in Marine Engineering,it connects the previous full depth numerical calculation and model test of the late.Truncation design of mooring system based on NSGA-? method,can find the optimal solutions quickly and accurately;at the same time,the model test method and test results are reliable and accurate,which can provide some reference for the relevant engineering design and theoretical research.