平衡大气边界层理论在复杂地形风场模拟中的应用

APPLICATION OF EQUILIBRIUM ATMOSPHERIC BOUNDARY LAYER THEORY TO SIMULATION OF WIND FIELDS IN COMPLEX TERRAIN

针对大气边界层数值模拟时入口湍动能及耗散率在下游持续衰减的问题,基于标准k-ε模型及其改进模型研究不同湍流黏性更新方法对平衡大气边界层自保持性的影响,然后采用平衡大气边界层自保持性方法结合建筑绕流影响区(BIA)问题解决方法对Askervein山绕流问题进行模拟研究,最后基于数值模拟结果,分析复杂地形绕流对风力机选址的影响。结果表明,选择合适的湍流黏性更新方法、粗糙度处理方法、湍动能和耗散率方程源项可使出口处的流动参数与入口处给定初值保持较高的一致性;BIA问题解决方法的引入可进一步提高复杂地形绕流模拟精度;风力机宜安装在山顶,避开湍流度较大的山体背风区,山后风力机的排布应结合山顶风力机尾流和山体影响区域综合考量。

There is a decay phenomenon that the value of turbulent kinetic energy in the outlet is inconsistent with that given in the inlet when simulating the atmosphere boundary layer with the standard k-εturbulence model.This paper uses different turbulent viscosity updating methods to research the sustainability of the equilibrium atmosphere boundary layer,then selects the better sustainable equilibrium atmosphere boundary layer methods combined with the solution of the BIA problem to simulate the wind flow over complex terrain,and finally based on the numerical simulation results,the effect of wind flow over complex terrain on wind turbine siting is analyzed.The results show that the wind profile at the outlet,the turbulent kinetic energy,and the dissipation rate can keep a high consistency with the given initial values at the inlet by selecting appropriate turbulent viscosity updating methods,roughness treatment methods,and the source terms of turbulent kinetic energy and dissipation rate.The introduction of the BIA problem-solving method can further improve the accuracy of numerical simulation of complex terrain.The wind turbines are preferably installed at the top of the mountain,avoiding the leeward area of the mountain with large turbulence,and the layout of wind turbines behind the mountain should be considered in combination with the wind turbine wake at the top of the mountain and the influence area of the mountain.