Generation of inflow data for inhomogeneous turbulence
Generation of inflow data for inhomogeneous turbulence
复制标题
生成非均匀湍流的流入数据
DOI：
10.1007/s00162-004-0147-z
复制
发表时间：
2004
影响因子：
3.4
通讯作者：
H. Andersson
中科院分区：
文献类型：
--
作者：
P. S. Johansson;H. Andersson
对于平面槽道湍流，只对能量最大的涡通过求解发展方程来产生入流边界条件。的动力学系统是由Galerkin投影的Navier-Stokes方程到子空间上的各种集合的最充满活力的模式从一个适当的正交分解（POD）相同的流量。低能量的小尺度POD模式随机添加，以便在高波数范围内施加一些能量。这被认为是至关重要的，以便更迅速地建立正确的耗散水平，并实现更现实的速度分量之间的能量分布。在R*=180的DNS和R*=400的LES上测试该方法。在入口下游1500个壁单元内，平均速度、均方根剖面、湍流剪应力和能谱等统计数据接近充分发展状态。
Inflow boundary conditions for turbulent plane channel flow are generated by solving evolution equations only for the most energetic eddies. The dynamical systems are derived by Galerkin projecting the Navier-Stokes equations onto the subspaces spanned by various sets of the most energetic modes from a proper orthogonal decomposition (POD) of the same flow. Low-energy small-scale POD-modes are added randomly in order to impose some energy in the high wave number range. This is found to be crucial in order to more rapidly establish the correct level of dissipation and achieve a more realistic distribution of energy between the velocity components. The method is tested on a DNS of R*=180 and a LES of R*=400. Statistics such as mean velocity, rms-profiles, turbulent shear-stress and energy spectra become close to the fully developed state within 1500 wall units downstream the inlet.