Bolund岛的DES数值模拟研究

Numerical simulation of the Flow Over Bolund Based on DES

目前很大一部分风电场都处于复杂地形中,处于山后的背风区域具有大分离的流动特征。为把DES方法应用到复杂地形模拟中去,采用带有壁面函数的DES方法对具有几乎垂直的悬崖地貌特征的Bolund岛进行了数值模拟。计算中采用了不同密度的网格。计算采用中心差分格式。在山后的大分离区,当网格大小为山高的5%时,可以获得很好的计算结果。在模拟大分离流动时,DES较RANS模拟方法具有显著的优势。

Nowadays,a large part of wind farms are located in complex terrains.The flow behind hills has large separation characteristics.In order to use detached eddy simulation in the simulation of flow over complex terrain,Bolund Island with an almost vertical upstream escarpment was simulated using DES with wall function.Computational domains with different density grids were utilized.Flow structure details and good results can be obtained when the grid size is a 5% smaller than the height of the island in large separation region,when using central scheme.DES has better performance than RANS in large separation region.