Hi, friends:

I just came across a problem in my research on Large Eddy Simulation. For my code of LES, I used to use implicit filter for my grid level filtering, which actually is no filtering at all. Now I wanna use a new explicit filter, does that mean I should filter the solution at each time step. However, I do notice that after applying the filter to the N-S equations, what I solve for are the resolved variable. Is it correct for me to filter the resolved quantities again and again at each time step? I just feel confused about this point. Can anybody give me some guide with his experience or some reference? Thanks a lot.

Hi yang,

when you use so called implicit filter, you will not bother about the type of filter you use. because implicit filter is just a averaging process. but when you use explicit filter then u have to bother about the filter type you want to use. Due to explicit filtering sub grid scale terms are depends on the type of the filter u use. refer CTR-standford papers for more clarification. bye rajani

Thank you, Rajani. I will follow your suggestion.