||September 3, 2008 10:18
Re: Is it feasible to apply implicit scheme in LES
I am not familiar with GMRES, but there is no fundamental reason that you can not use an implicit scheme. The issue is accuracy versus computational time. Your code has discretization errors due to your grid size and your time step size. For an implicit scheme, you can take very large time steps. This combined with the fact that implicit schemes are generally 1st or 2nd order means your error in the time discretization could be significant. So taking large time steps may not be a good thing. If this is the case you might as well use a faster explicit method and save on cpu time. The only way to check to see if this is the case is to do a time step study (similar to a grid study). Halve the time step and recompute. If the solution is unchanged, you are good.