Analysis and Numerical Simulation on Vortex-induced Vibration of Flexible Risers
|School||Ocean University of China|
|Course||Port, Coastal and Offshore Engineering|
|Keywords||Top sheets riser Vortex-induced vibration Flexible riser Fluid-structure interaction ANSYS-CFX|
Marine oil exploitation, for Economic and flexibility considerations, often a platform to connect more than one pipeline, for example, the top sheets riser, resulting in the mutual coupling between the riser and anchor chain, supply lines, and platforms, mutual effects, particularly in a limited area on many risers. Riser collision caused damage may reduce the life of the riser, and even endanger the security of the platform. Increase of as much as possible in a limited area on the platform riser, while avoiding collide with each other between the riser and excessive vortex-induced motion, a result of the interaction between multiple riser significance. Marine riser in the ocean current role, a regular vortex shedding, opposition tube there will be periodic pulsations role, resulting in the vortex-induced vibration, will result in the production and destruction of life, it will affect the riser severe cases, endanger the normal working of the platform. The marine riser fatigue caused by vortex-induced vibration damage not only by the attention of many scholars. Research and analysis in this regard the use of a physical model experiments and numerical simulation, the model experiment requires a lot of time as well as human and material resources, there are a lot of problems. In this paper, the finite element to calculation software ansysll comprehensive analysis of numerical simulation of vortex-induced vibration phenomenon of single riser with multi-riser. This paper is divided into three parts, the first on the basis of the previous study, the use of computational fluid dynamics software cfx 2-dimensional case, the single riser and different centers from the lower horizontal flow double riser vortex induced vibration problems, compared The analysis of the problems of the lift and horizontal drag force changes, as well as the cycle phase, draw reliable conclusions, to verify the correctness of the numerical method. Second, the study of the flow around a three-dimensional rigid dual riser compared with two-dimensional numerical simulation, more in line with the actual conditions close to the real problem, the findings and conclusions of the analysis, better guidance on practical problems . Finally, there is the main focus of this paper, that the numerical simulation of 3-dimensional flexible-riser, comparison, analysis of lift and lateral drag coefficient changes with 3-dimensional fixed multi-riser. Reliable results not only come in the course of the study, and also made some useful discoveries, and provides an important basis for practical problems for marine engineering.