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本文求解了雷诺平均Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程，湍流的模拟采用了标准的两方程（ｋ－ε）模型、修正的两方程模型、亚格子模型的大涡模拟三种模型。采用有限体积方法离散求解Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程。对流项的计算采用三阶迎风格式。为了提高求解过程的稳定性，采用显隐式混合格式来获得主对角元素区域占优。采用压力校正算法来求解最终的方程。计算了四种类型的小轿车外流气动特性。计算了后部配置尾翼时的轿车气动力特性。给出了流动速度矢量图、压力分布图及不同湍流模型间的比较图。数值计算结果和实验结果具有合理的一致性。用数值模拟手段给出了地面效应和影响。给出了装配后部尾翼时对整车气动力特性影响的计算结果。
This paper solves the Reynolds-averaged Navier-Stokes equations. The turbulent simulation uses three models of standard two-equation (k-ε) model, modified two-equation model and large-eddy simulation of sub-lattice model. The Navier-Stokes equations are discretely solved by the finite volume method. Convection terms are calculated using the third-order windward format. In order to improve the stability of the solution process, explicit dominant hybrid format is adopted to obtain dominant diagonal elements. The pressure correction algorithm is used to solve the final equation. The aerodynamic characteristics of four types of cars are calculated. The aerodynamic characteristics of the car are calculated when the rear wing is configured. The flow velocity vector, pressure profile and comparison between different turbulence models are given. The numerical results and experimental results have reasonable agreement. The ground effect and influence are given by numerical simulation. The calculation results of the aerodynamic characteristics of the complete vehicle when the rear tail is assembled are given.