Implementing "simpleFoam" in OpenFOAM

sagnikmazumdar · October 27, 2012, 12:16

Hi, we have been trying to simulate flow in a big domain with a single get. The computational domain is only a 2(degree) wedge. I have shared the case setup files in:

http://dl.dropbox.com/u/58859393/HCG_simpleFoam.zip

We are trying to get initial steady-state conditions for URANS and/or LES. For that we tried to used "simpleFoam"with "Realizable k-e Model". We observe that the center line velocity and k of the jet just blows up (1000 time of inlet) with the settings that we are using. I wonder if anyone could suggest what is going wrong with the problem setup? It would be of great help.

Thanks a lot.

Sagnik

matthi · October 30, 2012, 05:56

Dear Sagnik,

I don`t really understand what you want to do.
What means "domain with a single get" ???

If I understand the geometry you use a wedge with an open angle of only 2 degrees. This is very small, because you have cells with the same angle.
From my experience the grid could be responsible for the problem.

Maybe you can upload pictures of the grid.
I don`t want ro register in dropbox to download any data.

You have also to inspect carefully your boundary conditions.
Perform only a few timesteps and then first check carefully the results.

Greetings Matthi

sagnikmazumdar · October 31, 2012, 11:47

Hi Matthi, Thanks. You do not need to download dropbox to access the files. Just click on the link. I think the mesh is fine as the setup is very simple. Its a big domain with only a single jet entering the domain at the center. I believe the problem is more due to how the problem is setup.

matthi · October 31, 2012, 17:27

Dear Sagnik,

I just downloaded the case and had a look into the files. For the first sight I can`t see anything wrong ...
I never tried the boundary type wedge and don`t know for what cases this boundary condition is applicable. It`s also not clear for me, why a symmetryPLane can be applied for "planeAxis". Therefore, it would be very helpful to have some pictures about geometry and grid. The discretization should be seen there.

Did you try a smaller inlet velocity with a small timestep and strong relaxation also for the equations for epsilon and nuTilda (0.3)?

Greetings Matthias

October 27, 2012, 12:16	Implementing "simpleFoam" in OpenFOAM	#1
sagnikmazumdar New Member Sagnik Join Date: Oct 2012 Posts: 28 Rep Power: 14	Hi, we have been trying to simulate flow in a big domain with a single get. The computational domain is only a 2(degree) wedge. I have shared the case setup files in: http://dl.dropbox.com/u/58859393/HCG_simpleFoam.zip We are trying to get initial steady-state conditions for URANS and/or LES. For that we tried to used "simpleFoam"with "Realizable k-e Model". We observe that the center line velocity and k of the jet just blows up (1000 time of inlet) with the settings that we are using. I wonder if anyone could suggest what is going wrong with the problem setup? It would be of great help. Thanks a lot. Sagnik

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October 30, 2012, 05:56		#2
matthi Member Matthias Hettel Join Date: Apr 2011 Location: Karlsruhe, Germany Posts: 31 Rep Power: 15	Dear Sagnik, I don`t really understand what you want to do. What means "domain with a single get" ??? If I understand the geometry you use a wedge with an open angle of only 2 degrees. This is very small, because you have cells with the same angle. From my experience the grid could be responsible for the problem. Maybe you can upload pictures of the grid. I don`t want ro register in dropbox to download any data. You have also to inspect carefully your boundary conditions. Perform only a few timesteps and then first check carefully the results. Greetings Matthi

October 31, 2012, 11:47		#3
sagnikmazumdar New Member Sagnik Join Date: Oct 2012 Posts: 28 Rep Power: 14	Hi Matthi, Thanks. You do not need to download dropbox to access the files. Just click on the link. I think the mesh is fine as the setup is very simple. Its a big domain with only a single jet entering the domain at the center. I believe the problem is more due to how the problem is setup.

October 31, 2012, 17:27		#4
matthi Member Matthias Hettel Join Date: Apr 2011 Location: Karlsruhe, Germany Posts: 31 Rep Power: 15	Dear Sagnik, I just downloaded the case and had a look into the files. For the first sight I can`t see anything wrong ... I never tried the boundary type wedge and don`t know for what cases this boundary condition is applicable. It`s also not clear for me, why a symmetryPLane can be applied for "planeAxis". Therefore, it would be very helpful to have some pictures about geometry and grid. The discretization should be seen there. Did you try a smaller inlet velocity with a small timestep and strong relaxation also for the equations for epsilon and nuTilda (0.3)? Greetings Matthias