基于CFD正交仿真的冲刷防治方法优化研究

桩基冲刷不但使桩基裸露,而且影响平台的侧向和轴向特性以及承载能力,因而冲刷防治在海洋平台维修中占有重要地位.通过正交实验设计,采用三维大涡模拟圆柱桩基冲刷导流防治方法.导流法是在桩腿上设置导流盘,减轻桩基冲刷.CFD仿真结果表明,导流盘的放置位置影响桩基周围决定沙土运移的海水流速,导流盘位置越低,冲刷防治效果越好.正交实验设计结合CFD仿真可有效减少仿真次数,找出防治方法关键参数并优化,适于老龄平台的延寿加固.

Orthogonal CFD Simulation based Optimization for Fluid Diversion in Scour Prevention

A numerical study of the scour preventions was proposed around a circular pile. The turbulence of three-dimensional flow was obtained by use of the Large Eddy Simulation (LES) model. And the experiment of orthogonal method was used in simulation design and analysis. Scour always makes pile foundation exposed, and affects both lateral and axial pile performance and capacity, so the scour prevention is an important thing in offshore platform maintain. A method of scour prevention called fluid diversion method was described with setting flow deflectors on the leg. The CFD (Computational fluid dynamics) results suggest that the flow deflector position of fluid diversion strongly influences the flow velocity near the pile, which is the main factor of silt transportation. When the flow deflector position of fluid diversion decreases, the flow deflected by flow deflector increases. Results obtained from the computer models demonstrate the combination of CFD simulation and orthogonal design is suitable for the scour prevention and can be used in prolong platform lifetime.