[david]

Hi everybody!

I'm trying to simulate a modified version of the mixerVessel2D case with MRFSimpleFoam. The stator should rotate with the same angular velocity as the rotor. For this reason I assigned all the cells to the cellZone rotor by modifying blockMeshDict.m4. I also modified constant/MRFZones so that the patch stator is rotating too.

Unfortunately I'm getting pretty high velocities and I don't know why.



Here are the modified files:

blockMeshDict.m4
MRFZones

Is it possible at all to simulate a Single Rotating Frame with MRFSimpleFoam or did I make a mistake? Any help would be really appreciated.

Regards
David

[david]

I forgot to say that I'm using a value of 314.157 for omega. The highest velocity should be around 31.5 m/s and not 60 m/s. Any ideas?

Thanks
David

[david]

Ok, sorry guys. I found the problem. It was my mistake ;-)

[dmoroian]

Hi David,
I just tried a similar case with yours and it works (omega =104.72 rad/s; radius = 0.514 m -> v = 53 m/s):


Dragos

[david]

Hi Dragos

Thank you very much for helping me. Unfortunately I can't understand why it worked with your case while it didn't work with my case??

My problem was that I didn't set up the case correctly. I found two different solutions for my problem:

Solution 1:
- Assign all the cells to cellZone rotor in blockMeshDict.m4
- Move the faces from patch stator to patch rotor and delete patch stator in blockMeshDict.m4

Solution 2:
- Assign the rest of the cells to cellZone stator.
- Modify makeMesh and the dict-files so that all the operations are made for rotor & stator.
- Change MRFZones in the following way:

2
(
rotor
{
patches (rotor);
origin origin [0 1 0 0 0 0 0] (0 0 0);
axis axis [0 0 0 0 0 0 0] (0 0 1);
omega omega [0 0 -1 0 0 0 0] 314.159;
}

stator
{
patches (stator);
origin origin [0 1 0 0 0 0 0] (0 0 0);
axis axis [0 0 0 0 0 0 0] (0 0 1);
omega omega [0 0 -1 0 0 0 0] 314.159;
}
)

Regards
David

[david]

Solution 1b:
- Assign all the cells to cellZone rotor in blockMeshDict.m4
- Change MRFZones in the following way:

1
(
rotor
{
patches (rotor stator);
origin origin [0 1 0 0 0 0 0] (0 0 0);
axis axis [0 0 0 0 0 0 0] (0 0 1);
omega omega [0 0 -1 0 0 0 0] 314.159;
}
)

[dmoroian]

Hello David,
From what I understand, you want to rotate everything, so you should assign all the cells to the rotor.
Basically, you are after a rotating rigid body solution.

Dragos

[david]

Hi Dragos

That is exactly what I wanted to do. My intention was to play with a simple case to understand it. Now I'm trying to simulate a pump impeller.

Regards
David