Reversing Fan Direction / Cyclic Boundary Conditions
 

Hello

I'm using a cyclic boundary condition with a fan boundary condition by supplying the pressure rise curve but unfortunately the fan flow is in the wrong direction. How can I reverse the fan direction ?

Thanks in advance

Hi David,
I had the same problem some time ago. I did some tests and report results here. Please, read everything till the end, hope you can find some good hints there.
Enjoy.

mad

Hi Mad

Thanks, I've seen that post but it refers to a model created using blockMesh. My mesh has been converted from a Fluent/Gambit file so I can't control the cyclic face master/slave in this way. I've tried a direct mesh conversion using fluent3DMeshToFoam with the cyclic defined as a fan and also converting a patch-a/patch-b pair and creating the cyclic using createPatch utility but no success. On a different model I got the right direction without any change so I think I am looking for a way to reverse the master/slave order.

Hi,
I faced the same difficulties, since I am not using blockMesh as well. With the software I am using, the patch order (master-slave) is set by the surface domain number, which is a consequence on the domain creation. For example let us say I have the following surfaces:
domain-1
domain-2
domain-3
domain-6
domain-7
and I want to make domain-6 cyclic. First I copy paste domain-6. A new domain is created: domain-4 (the first empty name on my domain list). As a consequence, domain-4 will be the master and domain-6 the slave. This works for my software (pointwise). Check if it is ok for Gambit as well.
cheers

mad.