Mechanical Behavior Of Fluid-solid Coupling And Rapid Analysis Method Of Lifting Pipe In Deep-ocean Mining System

In the Deep-ocean Mining System,the delivery of the mining resources is an important part.There are internal fluids and external wave and ocean currents flowing through the lifting pipe in the transport process.How to ensure the continuity and smoothness of the mining process is the key issue of the relevant research.Considering fluid-solid couping,dynamical behavior of the lifting pipe in a1000m deep-ocean mining system was studied theoretically, numerically and experimentally.Considering the fluid-solid coupling between internal,external flow field and pipeline system,the mechanical behavior analysis of the lifting pipe is carried out,and the establishment of fluid-solid coupling rapid analysis method is explored,which can provide a scientific basis for the design of the deep-ocean mining system.The main results and conclusions are as follows:1.Dynamic equations that is employed to analyze the mechanical behavior of fluid-solid coupling of the lifting pipe is established,and is discrete d by modal shape function.The discrete equation is solved by structure-wake oscillator model. The effect of internal flow rate,inner radius,outer radius,the top tension and the length of pipe on first four inherent frequency is studied.The influence of internal flow rate,the length of pipe,inner radius,outer radius,the top tension,the velocity of external flow on the response of lifting pipe and wake in vortex-induced vibration is also studied,too.2.Rapid kinetic analysis method for fluid-solid coupling behaviour of lifting pipe in deep-sea mining is established with the external and internal fluid coupling simplified in the purpose of economic and conservative analysis of vortex-induced vibration.3.ANSYS software in combination with rapid kinetic analysis method is adopted to carry out analysis for the lifting pipe under fluid-solid coupling,and the results is compared with the results of structure-wake oscillator coupling theory analysis.4.The basic principles of fracture mechanics is used to calculate fatigue life of lifting pipe under fluid-solid coupling. 5.The correctness and validity of this research is verified by experiment.