海上风机基础结构波流荷载研究

发布时间：2018-07-02 07:04

本文选题：OpenFOAM + 数值波流水槽　；参考：《天津大学》2014年硕士论文

【摘要】：海上风力发电在我国属于起步阶段，海上风电风机支撑结构建设有很多问题亟需进一步研究。海上风机支撑结构除了受风机传递的风荷载外，还受到波浪和水流共同作用，准确计算波流荷载对于海上风机结构的设计有着重要意义。因此，研究海上风机支撑结构在波流共同作用下的水动力荷载对于海上风电场建设具有重要的应用价值。本文基于开源程序OpenFOAM建立了三维数值波浪水槽与波流水槽，对波浪、水流、海上风机基础结构的相互作用进行了模拟研究，主要内容和结论如下。（1）将动量分布源造波法引入OpenFOAM，采用流体体积函数（VOF）方法捕捉自由水面运动，利用OpenFOAM中的两相流模型求解不可压缩的雷诺方程，建立了三维数值波浪水槽。（2）数值波浪水槽变化时空步长的算例测试结果表明，以下取值能在有限计算量的条件下获得较好的波浪模拟结果：水平方向步长取为1/100波长，波高范围内垂向空间网格数不低于10，，推荐网格长宽比为1.8左右，其余垂向网格上下均减疏；时间离散采用动态时间步，最大时间步长为1/100波浪周期，克朗数不超过0.2。（3）应用建立的模型模拟了波浪作用下直立圆柱周围的波高、流速和压强分布，模拟结果与实验值吻合较好，证明建立的三维数值波浪水槽能够较好模拟波浪与结构物的相互作用。（4）在数值波浪水槽的基础上，利用在底部设置入流和出流边界的方法建立了三维数值波流水槽，波流模拟结果与已有实验结果有较好的一致性。（5）将所建立的三维数值波流水槽模型应用于江苏响水海上风电复合筒型基础的波流荷载研究，分别分析了纯波、纯流、波流共同作用下筒型基础周围的流动特性和基础结构所受的荷载。
[Abstract]:Offshore wind power generation belongs to the initial stage in China. There are many problems in offshore wind turbine supporting structure construction that need further study. In addition to the wind load transmitted by the fan, the supporting structure of offshore fan is also subjected to the interaction of waves and currents. It is of great significance to accurately calculate the wave-current load for the design of offshore fan structure. Therefore, the study of hydrodynamic load of offshore fan supporting structure under the action of wave and current has important application value for offshore wind farm construction. Based on OpenFOAM, a three-dimensional numerical wave flume and a wave-current flume are established in this paper. The interaction of wave, current and offshore fan infrastructure is simulated and studied. The main contents and conclusions are as follows: (1) the momentum distribution source wave-making method is introduced into OpenFOAM, the fluid volume function (VOF) method is used to capture the free water surface motion, and the two-phase flow model in OpenFOAM is used to solve the incompressible Reynolds equation. Three-dimensional numerical wave flume is established. (2) numerical wave flume variation is measured by an example. Better wave simulation results can be obtained with the following values: the horizontal step length is 1 / 100 wavelength, the vertical spatial mesh number is not less than 10 in the wave height range, and the recommended grid aspect ratio is about 1.8. The other vertical meshes are thinned up and down, the time discretization is dynamic time step, the maximum time step is 1 / 100 wave period, and the number of kroner is not more than 0.2. (3) the wave height around the vertical cylinder under wave action is simulated by using the established model. The distribution of velocity and pressure is in good agreement with the experimental data. It is proved that the three-dimensional numerical wave flume can simulate the interaction between wave and structure. (4) on the basis of numerical wave flume, Using the method of setting inlet and outlet boundaries at the bottom, a three-dimensional numerical wave-current flume is established. The simulation results are in good agreement with the experimental results. (5) the established three-dimensional numerical wave-current flume model is applied to the study of wave-current loads on the composite cylinder foundation of Xiangshui offshore wind power plant in Jiangsu Province, and the pure wave and pure current are analyzed respectively. The characteristics of the flow around the cylindrical foundation and the load on the foundation structure under the interaction of waves and currents.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU476;TV139.2

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