[michael3000]

I started with the windAroundBuildings example from OpenFOAM.

This example has the following boundary conditions:
- inlet with type=fixedValue (left side of the cube)
- outlet with type=pressureInletOutletVelocity (right side)
- ground with type=wall
- front, back and top of cube with type=symmetry


Now I'd like do change it such that the wind can come from an arbitrary direction, or to put it differently, I'd like to put the buildings in a wind field with various directions. The wind does not change during one simulation run, I just want to investigate a scenery under different wind conditions.

I can of course change the wind direction just at the inlet, but that's not enough, since depending on the direction, the wind might also come in from the other walls of the cube or even the outlet.

Another idea is to leave the hex mesh with the boundary patches and boundary conditions as-is, but to rotate the objects inside the cube. That comes with the drawback that I have to re-calculate the mesh for every wind direction.

What would be the best approach to handle various wind directions?

[picpic]

Hi Michael.

Did you get any solution for this situation? May I ask for your final decision?

Best,
Pic

[piu58]

You may extend the area around the buildings and make all the boundaries to inletoutlet.
Then you may add an internal wall in form of a hole in the structure, far enough from the building. You may use this to generate the wind you need.

For wind from another direction you have to move this internal wall, but preserve the coordinates of the structure you are interested in. This facilitates the postProcessing and evaluation.

[picpic]

Originally Posted by piu58

You may extend the area around the buildings and make all the boundaries to inletoutlet.
Then you may add an internal wall in form of a hole in the structure, far enough from the building. You may use this to generate the wind you need.

For wind from another direction you have to move this internal wall, but preserve the coordinates of the structure you are interested in. This facilitates the postProcessing and evaluation.

That's a great idea, will try! But does it mains I need to regenerate the mesh after each simulation?
BTW, the simulation I'm dealing with is about wind around buildings, which we always set a patch of the computation domain as input/output. You got any suggestions?

Thanks again,
Pic

[piu58]

Normally, I use blockMesh and remeshing is not a great deal. If you use something different. Maybe there are tools which modify an existing mesh. setFields is one of them, but I don't know if it is appropriate.