Forward-facing step give different results in SonicFoam and rhoCentralFoam

Iain_symthe · December 19, 2016, 16:41

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, 05:19

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.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Unable to validate results with sonicFoam and rhoCentralFoam	lordvon	OpenFOAM Running, Solving & CFD	8	December 5, 2016 14:25
Can not use very high pressure with sonicFoam and rhoCentralFoam	vasava	OpenFOAM Running, Solving & CFD	3	September 22, 2016 02:49
Which equations are solved by rhoCentralFoam, rhoSimplecFoam and sonicFoam?	gamma_user	OpenFOAM Verification & Validation	1	April 19, 2015 12:13
sonicFoam vs rhoCentralFoam forwardStep tutorial	hk318i	OpenFOAM Running, Solving & CFD	2	March 12, 2015 11:15
rhoCentralFoam / sonicFoam	VSass	OpenFOAM Running, Solving & CFD	1	June 26, 2013 12:39

October 30, 2017, 05:19		#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.