尺度自适应模拟的网格尺度关联分析

采用尺度自适应模拟（SAS）对雷诺数3 900的圆柱绕流展开数值模拟，对比分离涡模拟（DES）的计算结果和已有文献中的实验数据，系统研究了SAS和网格尺度的关联性问题。详细研究了不同网格分辨率和展向计算域的影响，分析了冯卡门尺度在尾迹区的时均湍流统计特性和瞬时分布规律。结果表明:在相同的网格分辨率下，SAS预测的回流区长度小于大涡模拟（LES），表现出较早的剪切层失稳；网格加密后，SAS预测的回流速度增大、雷诺应力峰值降低，计算结果与Lourenco & Shih的实验结果相接近。此外，在相同网格分辨率下改变展向计算域大小对SAS结果的影响很小。对SAS的网格尺度关联分析可以为该方法的工业应用提供指导。 

Grid scale dependence analysis of scale adaptive simulation

Scale Adaptive Simulation (SAS) is used to study the flow around a circular cylinder at Reynolds number 3 900. SAS predictions are compared with the popular Detached Eddy Simulation (DES) and existing experimental data. The effect of grid resolution and spanwise domain size on SAS model performance are systematically analyzed, time-averaged turbulent statistics and instantaneous distributions of the von Karman length scale in the wake region are discussed in detail. It is concluded that the recirculation length of SAS is smaller than that of Large Eddy Simulation (LES) under the same grid resolution, indicating an earlier onset of instability in shear layer. Velocity magnitude inside the recirculation bubble increases and the peak value of Reynolds stress decreases with grid refinement for SAS simulation, which are in good agreement with the experimental data of Lourenco & Shih. Additionally, changing the spanwise domain size with the same resolution has little effect on SAS predictions. The investigations on the influence of grid resolution and the spanwise domain size on SAS model performance can provide guidance for industrial applications of the SAS method in future.