Circulation in fluent
 

I have a simple case of circulating fluid in which a chamber has an inlet and the outlet is connected back to the inlet. The fluid should circulate. What boundary conditions should i choose??

Haree.:)

Hi, Haree,
How are the inlet and outlet of the computational domain connected?

Hi xrs333,

Its a rectangular chamber in 2D at room temperature. Air at 70 degrees and inlet velocity enters through an inlet at the bottom of this chamber and leaves through the outlet at the top. The outlet and inlet are connected externally by a pipe. The air after exiting the chamber should pass through this pipe and re-enter the chamber through the inlet.:confused::confused:

Haree.:):)

But how is the fluid driven? And if is it possible to include the connecting pipe in the computational domain? What are you interested in the flow system?

Hi,

Sorry,I forgot to mention that there is a pressure jump at the middle of the pipe which may be a fan. The problem is that of a heating oven in which hot air is pumped into the heating chamber with a known inlet velocity. The air heats the contents of the chamber and passes out through the outlet and enters the recirculation pipe. The recirculation pipe has a fan that recirculates pressurized air into the heating chamber through the inlet. I tried using velocity inlet and outflow boundary conditions. Grid check in Fluent failed saying that inlet boundary conditions should not have two adjacent cell zones, which i guess is the mistake. My model has two cell zones adjacent to the inlet boundary- the recirculation pipe and the heating chamber. The same is the case with the outlet boundary.I need to know what boundary conditions will be appropriate.:confused::confused:


Haree.:)

I realize your trouble.

If you are interested in the flow in the chamber only, just keep the chamber as the computational domain, because the its inlet velocity is known. Another modelling scheme is to build a computational domain including the chamber and the pipe, and simulate the fan using the Fan Boundary Condition of FLUENT.

The inlet or outlet boundary should has adjacent cell zones on both side under no condition.

okay i ll try doing that. Thank you very much:):):):)

haree.

Its possible. You can give the periodic condition for inlet. :)