SLTS / CoEuler stability problems

deepblue17 · February 12, 2010, 11:46

I've run into stability problems if I'm using SLTS or CoEuler as ddt scheme. I'm using sonic(Turb)Foam in version 1.5, 1.5-dev and 1.6. The pressure and Temperature getting negative and the velocity is getting very high, if the local Courant value or alpha is larger than 0.003 (for this simulation and a time step of 1.0e-5). If I'm using global time steps the simulation is stable with a maximum Courant number up to 5.

Has anybody an idea why the simulation get's unstable? I've expected that I could use local Courant numbers at least up to 0.5 or something like that in the SLTS / CoEuler ddt schemes. The SLTS scheme seams to be a little bit more stable than the CoEuler scheme, but really not much.

immortality · February 24, 2013, 16:23

i have a compressible transient case with rhoPimpleFoam that don't converge.can i use SLTS for getting a convergence?what occurs if i use that?

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February 24, 2013, 16:23		#2
immortality Senior Member Ehsan Join Date: Oct 2012 Location: Iran Posts: 2,208 Rep Power: 27	i have a compressible transient case with rhoPimpleFoam that don't converge.can i use SLTS for getting a convergence?what occurs if i use that?