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dvolkind April 10, 2011 14:28

Flow regime identification
Greetings to everyone!

Can anyone please explain me how to identify the flow regime?
For example, if I have the flow properly resolved (or precise experimental data is available), so that all characteristics of the flow are known everywhere at every timestep, how do I determine whether the flow is laminar, turbulent or transitional?

Thanks in advance,

ghorrocks April 10, 2011 22:23

If turbulent it will have a turbulence spectrum covering a wide range of time and spacial scales. A laminar flow will have only a limited range of time and space scales.

dvolkind April 11, 2011 09:06

Thank You, Glenn! Could you please explain what is considered wide or limited range?

ghorrocks April 11, 2011 18:35

Go to your library and look at any textbook on turbulence modelling or turbulence theory. This is all basic turbulence modelling theory and should be explained in detail by any decent textbook. The text I use is "Turbulence modelling for CFD" by Wilcox, but there are many others.

dvolkind April 12, 2011 03:09

Thanks again! I'll try to find some books. It has become really difficult, because foreign technical books are no longer published since USSR(

ghorrocks April 12, 2011 07:32

Then you should be able to find a USSR turbulence textbook. There are lots of textbooks on the topic so I bet you can find a Russian one.

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