Hydrodynamic Coupling Analysis Of TAD Multiple Floating Bodies

The exploitation of offshore oil and natural gas has advantages of abundant reserves,advanced Marine equipment,high profit from commercial exploitation,and good prospects for development.At present,the offshore platforms are in the development of multi-function and large-scale,while the problems of large platforms in the process of drilling operation such as large size,complicated production,high cost and difficult maintenance are becoming more and more prominent.Faced with the needs of various production and living functions,the TAD multi-floating body system emerges at the right moment.Inevitably,the hydrodynamic problems of the system,such as hydrodynamic interference,water resonance and nonlinear full-coupling response,have also become one of the major problems in the ocean engineering field Through the analysis of hydrodynamic coupling characteristics,determining the better mooring scheme,reducing the risk of collision between multi-floating bodies and ensuring the efficient and reliable drilling operation have become the goal of the multi-floating body in the initial researching stage of ChinaBased on the three-dimensional potential flow theory,the existence of hydrodynamic interference of a multi-floating body system which is composed of a cylinder and a barge is preliminarily determined by comparing with the existing values and the experimental results of a paper.And the hydrodynamic coupling characteristics of this system are verified.Then the Hydrodynamic coupling calculation model of the multiple floating body system which is consisted of the auxiliary semi-submersible platform and tension leg platform is analyzed in the range of frequency domain.With the compared first order hydrodynamic results(including the first-order motion RAO,added mass,radiation damping,etc.),this paper determines the accuracy of the numerical model and the hydrodynamic coupling law of this system.After completing the frequency-domain calculation,this paper conducts a time-domain analysis of the mooring dynamic response of the TAD multi-floating body system with cross-type connection cable arrangement based on the SIMO module,and compares it with the corresponding platform motion response in the standby mode.It is found that the motion response of a single floating body is affected by the shielding effect of another floating body,which mainly reflects in the coupled additional mass.Finally,by comparing the motion response of TAD multi-floating body system between crossed and paralleled arrangement of the connection cable,it is determined that the arrangement of the cross-type connection cable is more conducive to the stability of TAD multi-floating body system.Thus,a better arrangement of multi-floating body connection cable is determined.