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-   -   Ceiling Fan in Room (https://www.cfd-online.com/Forums/openfoam-solving/131650-ceiling-fan-room.html)

LWhitson2 March 18, 2014 21:31

Ceiling Fan in Room
 
I am trying to set up a ceiling fan in a room with no windows or doors. The basic geometry is a square room of dimension L, W, H with a uniform mesh using blockMesh. I then utilize the createBaffles utility to make a single baffle in the center of the room to act as my fan. I copied the createBaffles dictionary from the heatTransfer/TJunctionFan tutorial and utilized this as a square ceiling fan. I then use buoyantSimpleFoam to solve the problem for 2000 iterations.

The problem I run into is that the flow through the baffle is not consistent and is completely checkerboarded. In one spot the flow will be upwards and in another it will be downwards. I would think that it would all be in the direction of the pressure jump. Any thoughts on this or could I possibly be doing something wrong?

I will try and post my case file in the morning of the problem.

fedvasu May 3, 2014 14:52

you need a cellset which is cylindrical
 
I hope you have a cylindrical rotating domain AMI (or baffle),
for the shape to be cylindrical you need an outer cylindrical cellset and also check the directionality of rotation (clock-wise or anti-clockwise)

massive_turbulence May 4, 2014 12:51

Quote:

Originally Posted by fedvasu (Post 489634)
I hope you have a cylindrical rotating domain AMI (or baffle),
for the shape to be cylindrical you need an outer cylindrical cellset and also check the directionality of rotation (clock-wise or anti-clockwise)

I might be wrong about this but AMI only works with pimpleDymFoam and not buoyantPimpleFoam, right?

fedvasu May 4, 2014 14:40

oh, sorry. I thought you were doing moving mesh.
AMI(mesh movement) works with only 'DyM' solvers.

still you need a cellset to define the cylindrical part. one approach is MRF, which doesn't include mesh movement, through fvOptions.


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