About CFL number !
 

The CFL number is function of three parameters, it's found for controller that the scheme is stable. The choice of the CFL infect the space time. In case of Roe scheme, the scheme is stable for 0 < CFL <=1. So far I think that all fine. In some meshes there will be no stable for value lower than 1, but they still need to be small, and even if it was in this interval was not necessarily stability

Could you explain it ! thanks

Re: About CFL number !
 

Are you using FVM code or finite difference code. Low courant number is not a stability requirement for FVM codes.

Usman

Re: About CFL number !
 

That's not correct. A low CFL number is not a stability requirement for implicit schemes, but an explicit FV scheme will still be CFL-limited.

Re: About CFL number !
 

ag is right! Sorry about that. For some reason i mixed up FV with implicit scheme.

Usman