Combined compressible flow and moving mesh with layers

andersking · September 2, 2008, 00:05

Hi,

I am trying to run a moving mesh simulation with compressible flow. The solver is based on sonicTurbDyMEngineFoam, but without the crank angle parts. Also I am trying to use a layered mesh for the moving mesh component.

Unfortunately my solution blows up after a new layer is added, as in the following images.

before added layer.

after added layer

.

Somehow the pressure is not getting updated correctly. I'm not sure if this is due to the new cells not receiving their correct value, or the fact that the added layer is too small (I have tried different layer thicknesses however.), also the large negative (absolute) pressures suggest that the pressure/temp values for the new cells are the problem. I have run this solver under 1.4-dev previously with no problems. Any help is appreciated.

Cheers,
Andrew

andersking · September 2, 2008, 00:08

PS. sorry for the large images. I meant to resize these first.

deepsterblue · September 2, 2008, 22:29

Have you looked at the actual cell pressure for the new cells? It would be more useful if you provide cell data and not point-interpolated pressure. Looks like this is a mapping issue, but I can't be sure. Also, since you mention that it worked with 1.4-dev, I'm assuming that you're using 1.5 now?

abminternet · December 1, 2010, 06:29

Hi Andrew,

I'm also trying to set up a case with sonicTurbDyMEngineFoam, but as I'm an OpenFOAM newbie, and as I can't find any tutorial or info on the net, I haven't got very far. Would you mind to share a bit of your knowledge? what do the entries on the dictionaries mean, or what dictionaries do I need? or any idea as where to find some info? Thanks a lot.

abminternet · March 1, 2011, 10:40

Hi Andrew and Sandeep,

did you happen to find out the problem with pressure? I am also using sonicTurbDyMEngineFoam, and I notice the same effect, pressure doesn't seem to be changing. When both valves are closed, pressure remains constant inside the cylinder, as soon as one of the valves opens, pressure in all of the cylinder changes to adopt the pressure in the port whose valve just opened. Any ideas?? I would greatly appreciate it.

September 2, 2008, 00:05	Hi, I am trying to run a m	#1
andersking Member Andrew King Join Date: Mar 2009 Location: Perth, Western Australia, Australia Posts: 82 Rep Power: 17	Hi, I am trying to run a moving mesh simulation with compressible flow. The solver is based on sonicTurbDyMEngineFoam, but without the crank angle parts. Also I am trying to use a layered mesh for the moving mesh component. Unfortunately my solution blows up after a new layer is added, as in the following images. before added layer. after added layer . Somehow the pressure is not getting updated correctly. I'm not sure if this is due to the new cells not receiving their correct value, or the fact that the added layer is too small (I have tried different layer thicknesses however.), also the large negative (absolute) pressures suggest that the pressure/temp values for the new cells are the problem. I have run this solver under 1.4-dev previously with no problems. Any help is appreciated. Cheers, Andrew __________________ Dr Andrew King Fluid Dynamics Research Group Curtin University

September 2, 2008, 00:08	PS. sorry for the large images	#2
andersking Member Andrew King Join Date: Mar 2009 Location: Perth, Western Australia, Australia Posts: 82 Rep Power: 17	PS. sorry for the large images. I meant to resize these first. __________________ Dr Andrew King Fluid Dynamics Research Group Curtin University

September 2, 2008, 22:29	Have you looked at the actual	#3
deepsterblue Senior Member Sandeep Menon Join Date: Mar 2009 Location: Amherst, MA Posts: 403 Rep Power: 25	Have you looked at the actual cell pressure for the new cells? It would be more useful if you provide cell data and not point-interpolated pressure. Looks like this is a mapping issue, but I can't be sure. Also, since you mention that it worked with 1.4-dev, I'm assuming that you're using 1.5 now? __________________ Sandeep Menon University of Massachusetts Amherst https://github.com/smenon

December 1, 2010, 06:29	howto sonicTurbDymEngineFoam	#4
abminternet Member Join Date: Nov 2010 Posts: 86 Rep Power: 16	Hi Andrew, I'm also trying to set up a case with sonicTurbDyMEngineFoam, but as I'm an OpenFOAM newbie, and as I can't find any tutorial or info on the net, I haven't got very far. Would you mind to share a bit of your knowledge? what do the entries on the dictionaries mean, or what dictionaries do I need? or any idea as where to find some info? Thanks a lot.

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March 1, 2011, 10:40		#5
abminternet Member Join Date: Nov 2010 Posts: 86 Rep Power: 16	Hi Andrew and Sandeep, did you happen to find out the problem with pressure? I am also using sonicTurbDyMEngineFoam, and I notice the same effect, pressure doesn't seem to be changing. When both valves are closed, pressure remains constant inside the cylinder, as soon as one of the valves opens, pressure in all of the cylinder changes to adopt the pressure in the port whose valve just opened. Any ideas?? I would greatly appreciate it.