[padmanathan]

Hi all,

I am trying to simulate supersonic swirling flow in a pipe to analyze the flow characteristics inside and after the exit of a pipe. i'm getting error while creating face mesh, 'coz the pipe exit edge is shared by free stream. So, How to choose boundary or create mesh.

I have chosen 2D axisymmetric flow, and the flow inside pipe is considered as supersonic and exit to atmosphere.

Herewith i Have attached geometry, which gives you the idea of the problem!

Thanks in advance,
padhu

[-mAx-]

I don't have experience on supersonic swirling flow, but regarding the modeling side, if the surfaces are connected (surfaces separated on your red line), then gambit should set the edge as internal (default). Just don't set this edge as special BC.
Now if your surfaces have 2 different physics, you can define them as separated continuum (fuid domains)

[padmanathan]

thank you max,
If two faces sharing the same edge, how we can set boundary?, 'coz particular edge is outlet to pipe and inlet to freestream.

once again Thanks ,
padhu

[-mAx-]

go to Boundary condition panel and select the edge as entity.
But once again, I wouldn't set this edge as special boundary. Just let it, it will be assimiled as interior.
Setting it as outlet won't be correct since you have behind it a meshed domain where your fluid is free to move

[padmanathan]

Thankyou Max,

I didn't find the option entity in both gambit as well as in fluent to set boundary in the edge .

excuse me for the delayed reply.
padhu

[-mAx-]

excuse me for the more delayed reply (back from holidays)
you can find what you want in gambit: Zone/specify Boundary Types

[padmanathan]

Thank you, Max. I will try and reply soon.