【摘要】 基于RANS方法构造满足水平均匀性的自保持平衡大气边界层是计算风工程中一个非常重要但尚未得到很好的解释和解决、同时也经常被忽略的前提问题。本文从描述湍流流动的模型方程角度对这个问题进行了研究。首先基于湍流平衡假设,从两方程标准k-ε模型导出一类近似满足大气边界层自保持要求的湍流来流边界条件;接着将本文建议的此类边界条件运用到模拟钝体建筑结构分离流动具有较好适用性的SST k-ω湍流模型中,通过数值风洞模拟对比算例,验证了作者提出的边界条件在构造自保持平衡边界层中的适用性。通过本文的理论和数值研究,一方面对研究平衡大气边界层的模拟问题提供了一种新的方法,另一方面也为风工程数值模拟提供了一类新的适用的来流湍流边界条件,将对增进计算风工程中模拟平衡边界层的理解有所帮助,因此具有理论和实用价值。更多还原

【Abstract】 Constructing the equilibrium atmosphere boundary layer is an important yet still unsolved problem in the numerical simulation based on Reynolds Averaged Navier-Stokes(RANS) method for Computational Wind Engineering(CWE).This problem is reinvestigated from a new viewpoint using turbulence models.A set of new inflow turbulence boundary conditions is presented based on the standard k-ε model after an approximate solution is derived from the Turbulence Kinetic Energy(TKE)equation.The fact that the suggested inflow turbulence boundary conditions may produce horizontally homogeneous equilibrium ABL in SST k-ω model is verified and validated.Therefore,the proposed approach is more suitable for numerical simulation of the bluff body flows.A new method of modeling equilibrium ABL is introduced and a set of inflow turbulence boundary conditions are presented for practical applications.更多还原