旋转盘腔紊流流动的数值研究

Numerical study for turbulent flow inside rotating disc cavities

关键词:  旋转盘腔  湍流模型  数值仿真

Key words:  Rotating disk cavity  Turbulence model  Numerical simulation

摘要:

为了比较近壁紊流模型对旋转盘腔内流动特征模拟精度的影响,采用在核心区选用标准k-ε模型、在近壁区选用单方程和Launder-Sharma两方程两种低雷诺数模型的区域紊流模化方法,对具有径向出流的转—静盘腔和具有径向出流的共转盘腔结构的流动进行了数值计算研究。计算结果表明:在计算的两个算例中,前者采用近壁单方程模型要稍优于两方程模型,后者采用近壁两方程模型要明显优于单方程模型,因此近壁区紊流特性的处理对旋转盘腔内的流场模拟精度具有重要的影响。

Abstract:

To investigate the effectiveness of turbulence model near wall on the flow nature inside a rotating disc cavity, the zonal modelling approach was applied for the computation of flow inside a rotor-stator disc cavity with radial outflow and a co-rotating disc cavity with radial outflow. In the core region of the cavity the standard k-e turbulence model was employed. In the near wall region two low Reynolds number turbulence models were employed, they were single equation model and Launder-Sharma two equations. The results showed that the k-e /1-eqn predictions appear to be in closer agreement with the experimental data for the ro-tor-stator case, whereas for the co-rotating case, the Launder-Sharma low Reynolds number turbulence model is obviously superior to the single equation model. The treatment of near-wall turbulent characteristics seems to be very important to the simulation accuracy.