用预处理方法数值模拟街区峡谷内的污染物扩散
Preconditi oning for numerical simulation ofpollutant dispersion in street canyon
-
摘要: 通过耦合求解二维可压缩Navier-Stokes(NS)方程和k~ε湍流模型方程及平流扩散方程,数值模拟了街区峡谷(Canyon)内的低速湍流流场及大气污染物在其中的扩散。为了加快计算的收敛,对控制方程进行了预处理。预处理后的NS方程的求解采用LU-SGS隐式方法和JST中心差分格式。数值模拟结果表明预处理方法求解低速流场可加快收敛,同时就街区峡谷内的污染物扩散状况得出了有意义的结论。Abstract: Numerical simulation is made to calculate the turbulent flowfieldand pollutant dispersion in street canyon by solving the 2 -D compressible Navier-Stokes equations and k~ε model equations and tr ansportation-dispersion equation. The LU-SGS implicit method