尺度参数对海上风机基础结构波浪力特征的影响

Scale effect on wave force characteristics of the structures supporting offshore wind turbines

为适应大容量海上风机的承载需求,支撑机构的尺度越来越大,在水动力学上可能介于小尺度和大尺度之间.对于这类中等尺度的结构,其波浪力的组成和计算方法对于海上风电工程设计十分重要.本文通过建立数值波浪水槽,对直立圆柱在线性波条件下的波浪力进行数值模拟研究.通过分别求解带自由面的Navier-Stokes(N-S)方程和Euler方程,准确分离黏性力与惯性力,详细探讨了黏性力和惯性力随圆柱尺度比的变化规律,给出了各自表现显著的尺度区间,定量分析了忽略黏性力或绕射力产生的误差.据此提出了中等尺度的概念,并给出了不同尺度结构波浪力的计算方法.

In order to meet the pressing requirements of large-capacity offshore wind turbines, the scale of foundation structures tends to be larger and larger. These large structures may be hydrodynamically neither small scale nor large scale. For this type of intermediate scale structures, it is significant for offshore wind turbine design to figure out the wave force composition and the calculation method. This paper establishes a numerical wave tank, and analyzes wave force on a vertical circular cylinder by numerical simulation. By solving the Navier-Stokes equations and the Euler equations respectively, the viscous force and inertia force are separated reasonably. Furthermore, the law of viscous force and inertia force varying with the scale of cylinder is discussed. Finally, the significant scale intervals of marine structures and their wave force calculation methods are given.