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Bo Jensen March 8, 2007 03:44

Boundary layer thickness in pipe entrance
 
Hi all

I am trying to find the equations for the boundary layer thickness from pipe entrance to fully delveoped turbulent pipe flow. I have found one, but it gives me a boundary layer thickness at large distance from the inlet (but still lower distance than that of the enrance length) that is aover half the diameter of the pipe.

Could some please help

Adam Adamkowski April 2, 2007 05:12

Boundary layer thickness in pipe flow
 
Hi, I am interested in the boundary layer thickness in fully delveoped turbulent pipe flow. Could you give me aproximete formula which allow me to estimate the boundary layer thickness in pipe flow in depending on the Reynolds number. The smooth pipe can be assumed. or totally .

Trinity April 6, 2007 22:53

Re: Boundary layer thickness in pipe flow
 
Hi,

its difficult to type out the formula here. But there is an extension of the Law of the Wall to internal flows such as pipe flow. Nikuradse equation gives the dependence of velocity on r over a large region of the flow except the sublayer.

Check out Chapter 13 of 'Convective Heat and Mass Transfer' by Kays and Crawford.


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