Hi Kamil, In general ImexOrder2 is best but since the Reynolds number is probably quite low for this case you may well get away with ImexOrder1. Cheers, Spencer. On 17 Nov 2014, at 14:28, Kamil ÖZDEN <kamil.ozden.me@gmail.com<mailto:kamil.ozden.me@gmail.com>> wrote: Dear All, Which one of the time integration schemes for Incompressible Navier Stokes Solver (pg. 62 in user guide of Nektar++) should be preferred to solve a problem related with blood flow in a stenosed vessel? Regards, Kamil _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052