Periodic Boundary
 

Hi

I am simulating a flow in a square duct with four cubes inside it. I want to set up a periodic boundary condition for my flow. In order to do that i first created a domain interface for inlet and outlet and set a translational peridocity as interface model. I have following questions:

1) Do i have to specify change in pressure? If yes how can i calculate it.

2) I would like to specify constant pressure gradient of -1.59 Pa m^-1. How can i do that!

Thanks for your help!!

Re: Periodic Boundary
 

Hi,

1) You need to specify something to get the flow moving!

2) From your other posts it looks like translational periodicity with a pressure difference might be appropriate. If your duct is 1 metre long then my guess is the pressure drop would be 1.59 Pa. I will let you guess what the pressure drop is for other lengths.

Glenn Horrocks

Re: Periodic Boundary
 

Can i not specify constant pressure within every cell of my domain to get the flow moving. Thats what they seem to have done in the paper. But my problem is i dont quite know how to do it! If anyone out there can give any input it will be very helpful. I am using LES smagorinsky model!.

Mann

Re: Periodic Boundary
 

Hi,

As previously stated setting a constant pressure gradient per cell cannot be done. This is especially so if you are doing a LES simulation! You need the pressure field to couple with the velocity field to get something of physical meaning.

Glenn Horrocks