fully developed flow simualtion with fluent
 

Hello everyone
I am trying to do a very basic simulation. It is to obtain fully developed flow in a square duct of constant cross section.I want to use the periodic bcs so I don't need to build a very long duct.
The size is 0.1mX0.1mX0.05m. And I have generated 20 cell in the flow direction.I choose water as the flow material.And I combine inlet with outlet to a new boundary of type periodic in fluent .Then I set the mass flow rate to 0.01, but after calculation the result is not good.
The attached file is my .cas file and .msh file.Inlet and outlet have been combined to a new boundary in .cas file.

Can you analyse it for me? thank you very much!

regards!

bryant

I am sorry the size is a little big so I can not upload it here.I have tried my best to upload my case in a website.Here is the link:
http://ishare.iask.sina.com.cn/f/35299711.html

click the green button to download.

Thank you!

In order to reduce your problem, did you use symmetry in your duct model? See attached picture.