Fluid-solid Coupling Analysis of Riser based on CFD

Abstract

The riser is the only channel connecting the submarine pipeline oil gas and offshore platform structures, offshore oil and gas development and utilization of lifelines, offshore pipeline system is the weakest vulnerable link. Due to its long and thin structure, the marine riser is easy to failure and failure in the complex working conditions. Marine vibration pipe safety or not directly affects the marine engineering and the surrounding environment and marine biology, in the event of damage, can cause the economic loss and environmental pollution, will result in a casualties, and even cause serious secondary disasters. Therefore, the safety and reliability of marine riser has been the focus of marine oil and gas industry research. In order to ensure the safety and reliability of the marine riser, it is usually necessary to evaluate the safety and reliability of the marine riser. The two-way fluid-solid coupling analysis of the riser system with a water depth of 500m is carried out by Ansys workbench software. The results show that the maximum flow rate of the flow field at the interface between the fluid and the riser occurs in the middle of the riser near the two ends. As time increases, the maximum flow rate will gradually shift from both ends to the middle of the riser, and the maximum value is 0.85m/s; the maximum stress of the riser will appear at the upper and lower end points, the maximum is 81.43Mpa; the lateral displacement of the upper end of the riser reaches the maximum, about 0.69m; indicating that these positions are the vortex induced lateral vibration of the riser dangerous area; therefore, this part can be improved by structural design or protection to increase the working life of the riser.