modeling fluid in pipe
 

In modeling fluid flow in a pipe, when do I need to see the fully developed flow? (either of laminar or turbulent regime)
Do I need specific length in inlet or outlet?
What is the criterion for that?
I was thinking that if after any modeling there wouldn’t be any circulation (which cause back flow) in openings the length is enough (either of inlet or outlet), is it true?

hi hamid

I have a problem like yours. I want to simulate laminar-turbulent transition pipe flow through LES model in FLUENT 12. I want to simulate fluctuation ( pressure and velocity ) at the antrance region and want to see the laminar and transitional region.This is my thesis study.
I dont know how can manage this one through LES model.
If you have any information about, can you help me.

thanks to you