Forward-facing step give different results in SonicFoam and rhoCentralFoam

Iain_symthe · December 19, 2016, 17:41

I tried running the forward-facing step tutorial case using sonicFoam and rhoCentralFoam for endTime = 20s with OF 4.1 on Ubuntu 14.04. At T = 20 the solutions have converged for both solvers. However the answers are different. The results don't agree well with the normal shock values for M = 3. Does anyone have any idea as to why this is so. Please see attached results.

eric · October 30, 2017, 06:19

Have you compared this against the literature data? If you look in the original paper for rhoCentralFoam, DOI: 10.1002/fld.2069, you will see some results for this case. Also, to get similar results in sonicFoam, you need to increase the grid size (and consequently reduce time step) a lot, since this solver is much more diffusive than rhoCentralFoam.

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October 30, 2017, 06:19		#2
eric Member Knut Erik T. Giljarhus Join Date: Mar 2009 Location: Norway Posts: 35 Rep Power: 22	Have you compared this against the literature data? If you look in the original paper for rhoCentralFoam, DOI: 10.1002/fld.2069, you will see some results for this case. Also, to get similar results in sonicFoam, you need to increase the grid size (and consequently reduce time step) a lot, since this solver is much more diffusive than rhoCentralFoam.