基于CFD与动态系泊模型耦合的漂浮式风机半潜平台运动响应数值模拟研究

Numerical simulation of motion response of a semi-submersible platform based on CFD coupled with dynamic mooring models

目前使用CFD方法计算浮式结构物的运动以及系泊线受力时,主要使用静态系泊模型,而静态系泊模型无法准确计算系泊线的张力。基于STAR-CCM+平台,使用重叠网格技术、DFBI多体运动模型以及VOF法捕捉自由面,通过求解N-S方程,对半潜式漂浮式风机半潜平台进行数值模拟研究。并以数据耦合迭代形式植入动态系泊模型,该模型可以充分考虑系泊缆张力、水动力载荷以及海床接触作用力。计算发现:与静态系泊模型相比,CFD和动态系泊模型耦合方法计算的半潜平台运动响应与之相近,系泊线张力响应相差较大;基于动态系泊模型的计算结果与试验结果更吻合。搭建的耦合方法计算精度高,与试验误差小,为浮式风机及其他浮式结构物的设计提供了一种高效精准的数值模拟方法。

Currently,when using the CFD method to calculate the motion of floating structures and the forces on the mooring lines,the main approach is to use a static mooring model,but the static mooring model cannot accurately calculate the tension of the mooring lines.Based on the STAR-CCM+platform,using the overset grid technique,the DFBI multi-body motion model,and the VOF method to capture the free surface,a numerical simulation study was conducted on a semi-submersible floating wind turbine platform through solving the N-S equations.A dynamic mooring model was also embedded in the form of data coupling iteration,which can fully consider the mooring cable tension,hydrodynamic loads,and seabed contact forces.The calculations show that compared to the static mooring model,the motion response of the semi-submersible platform calculated by the coupling method of CFD and dynamic mooring model is similar with it,but the mooring line tension response is quite different,and the calculation results based on the dynamic mooring model are more consistent with the experimental results.The established coupling method has high calculation accuracy and small errors compared to the experiment,providing an efficient and accurate numerical method for the design of floating wind turbines and other floating structures.