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Laminar and turbulent flow 
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#1
Aug2306, 09:08 PM

P: 3

Hi all,
can you tell me what different between "fully developed laminar flow" and fully developed turbulent flow"? 


#2
Aug2406, 02:09 AM

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PF Gold
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#3
Aug2406, 06:22 AM

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P: 5,095

Perhaps take a quick peek here:
http://www.physicsforums.com/showthread.php?t=92823 It could be that the OP was looking for something simple like a fully developed flow means a non changing velocity profile. The laminar profile is parabolic and the turbulent is essentially rectangular(ish). http://www.tpub.com/content/doe/h101...012v3_40_1.jpg 


#4
Aug2406, 08:44 PM

P: 3

Laminar and turbulent flow
Let consider the channels formed by Sshaped fins, as shown in the link. [URL="http://s3.photobucket.com/albums/y54/lamayuko/Sshaped%20fins/"]  A supercritical CO2 as working fluid flows inside these channels with Re ~ 10000. Do you think a fully developed turbulent flow exist?  A water as working fluid flows inside these with Re ~ 1000. Do you think it is the Fully developed laminar flow? 


#5
Aug2406, 09:01 PM

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EDIT: well, the transition to turbulence >may< depend on another scaling parameters, not only on the Reynolds, but also on the Richardson number as in the case of a buoyant flow, or on the Rosby number as in the case of a rotating system (The Earth). These three mechanisms (viscosity, buoyancy, and coriolis forces) are the main generators of uncontrolled vorticity eventually leading to turbulence. 


#6
Aug2406, 10:19 PM

P: 3

But how about fully developed flow? Can it exist in such flow channel configuration? 


#7
Aug2506, 12:56 AM

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Does it makes sense now?. 


#8
Mar1507, 10:34 AM

P: 12

Is it possible to have a “fully developed turbulent flow” over plate?
I am interested is incompressible subsonic flow and I know that the fully developed turbulent flow, i.e., constant velocity profile can happen inside pipes or channels or between two parallel plates. Does the boundary layer of turbulent flow over plate reach a constant value? If so how are boundary layer displacement and boundary layer displacement thickness obtained? Thanks 


#9
Mar1607, 04:27 PM

P: 11

Cheers 


#10
Mar1907, 08:39 AM

P: 12

You responded that it is possible to have a “fully developed turbulent flow over a single plate” and the only variable here is the Reynolds' number.
I am interested in FULLY DEVELOPED, which means its velocity profile does not depend on the streamwise coordinate. I would like to know if it really happens over a single plate and if I can assume that its statistics does not depend on the streamwise coordinate Thanks 


#11
Mar1907, 09:47 AM

P: 11

"Fully developed" flow is pipe/duct/channel flow terminology, and doesn't really apply to external flows. Nevertheless (and especially for flat plate), boundary layer thickness (dispalcement thickness, etc) can be thought as a function of Re_x=U*x/niu, where x is the streamwise distance to the leading edge. Cheers. // Rope 


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