浓缩风能装置内部流场仿真计算分析

An analysis of grid independence for internal flow field simulation of concentration wind energy devices

对浓缩风能装置模型Ⅰ所处流场进行仿真网格无关性分析,得出相关中心为fine,相关性为70时可以使计算相对误差最小,且计算时间消耗可以接受.采用仿真网格无关性分析结果对浓缩风能装置模型Ⅰ和模型Ⅱ进行流场仿真计算,并与车载实验结果进行对比分析,最终结果表明:两模型均可以浓缩风能,并能够提高风能的能流密度;采用网格无关性分析结果进行模拟计算,安装风轮截面处风速测量点风速模拟计算值与风速实际测量值的相对误差在5%、10%和20%以内的点所占百分比分别为41.67%、83.33%和91.67%,因此可以采用该结果对浓缩风能装置进行初步的定量分析,为浓缩风能装置中安装的叶轮之设计提供参考;采用该结果进行的模拟计算与车载试验均可得出模型Ⅱ优于模型Ⅰ的结论,因此该结果可以定性分析不同浓缩风能装置,以实现浓缩风能装置的结构优化.

The grid independence of the flow field in Model I has been analyzed and the simulation results show that the error rate of calculation result is the lowest when the relevance of the grid division is 70 and the relevance center is fine.The computing time is about 3h,thus acceptable.Therefore,to minimize the error, the grid division method is adopted to compute the simulating flow fields of Model Ⅰ and Ⅱ .When compared with the results of vehicle tests, the final results of this research show that the two models can concentrate wind energy and improve the energy density effectively. In the installation section of wind turbine, the point whose relative error between simulated values and measured values is less than 5 percent, 10 percent and 20 percent accounting for 41.67 percent,83.33 percent and 91.67 percent respectively.Therefore, the resuk of grid independence analysis can be used for the preliminary quantitative analysis of concentration wind energy device so as to provide reference for the design of impeller installed inside the device.And the simulation and experiment both conclude that Model Ⅱ is better than Model Ⅰ .Hence the qualitative analysis of different concentration wind energy device may be carried out to optimize the contour of concentration wind energy devices by this method.