Help! How to set boundary conditions of this model???
 

hello,everyone. I have a problem about boundary conditions.
here is the picture.

requirements:
The first condition: the boundary conditon of pipe face 1 is "exhaust", the air could flow into pipe through pipe face 2, so how to set the boundary conditions of roadway face 1 and roadway face 2.

The second condition: the boundary conditon of pipe face 1 is "pressure-inlet", the air could flow into roadway through pipe face 1, so how to set the boundary conditions of roadway face 1 and roadway face 2.

What is roadway #? Are you trying to simply simulate an exhaust within a domain?

thank you,lovecraft.
the model is that a pipe is in another volume/domain(roadway),so there are two pairs of faces,namely 4 faces, they are pipe face 1 and roadway face 1, pipe face 2 and roadway face 2.
now, if the boundary conditon of pipe face 1 is "exhasut",how to set the boundary conditon of roadway face 1 to let the air flow into the roadway???
hope for your reply.

thank you,lovecraft.
the model is that a pipe is in another volume/domain(roadway),so there are two pairs of faces,namely 4 faces, they are pipe face 1 and roadway face 1, pipe face 2 and roadway face 2.
now, if the boundary conditon of pipe face 1 is "exhasut",how to set the boundary conditon of roadway face 1 to let the air flow into the roadway???
hope for your reply.

Not sure I understand… you want air to be subtracted from the roadway and air to be added to the pipe but the air that goes out of the roadway is not the same air that enters the pipe, is that correct?

air is in the roadway, I want the air to be subtracted into the pipe from pipe face 2 and flow out of pipe from pipe face 1.
so I could set the boundary condition of pipe face 1 to be "exhuast fan" to offer "suction power" to subtract the air around pipe face 2.
but as the adjacent face, how to set the boundary condition of roadway face 1??
hope you could understand.

What is it like in the real case? Is there a fan there?

yes, there is a fan at the end of pipe face 1 and I just set the boundary condition of pipe face 1 to be "exhuast fan" to describe the fan.

Can't you just set an inlet and an outlet on the two sides of the fan?