@浪迹天大 是这样的，我最近也在读OpenFOAM中LES模型，发现Lund提到
The nearly universal approach is to simply write down the filtered Navier-Stokes equations together with an assumed model for the subgrid-scale stresses and then apply the desired spatial discretization to this “filtered” system. Although it is rarely mentioned, what one is doing by adopting this procedure is to imagine that the finite support of the computational mesh together with the low-pass characteristics of the discrete differentiating operators act as an effective filter. One then directly associates the computed velocity field with the filtered velocity. This procedure will be referred to as implicit filtering since an explicit filtering operation never appears in the solution procedure.
也就是说OpenFOAM程序除了动态模型外都没有对N-S方程进行显式的滤波操作，那么我们在方程植入中只要修改$\nu_{sgs}$就OK了，我在后面会做几个滤波函数的选择的对比，看看最后结果一样不一样
用STARCCM做船舶阻力分析，考虑升沉和纵倾，之前流域底部设置为速度入口，结果会收敛。考虑浅水效应即流域底部的影响时，我把底部的边界条件修改为壁面 结果不收敛 且提示如图警告-the mesh may have non-positive volume cells，请问前辈是壁面条件不能修改为壁面而是其他，还是修改为壁面后需要再修改其他的地方，谢谢
