# Reynold's number calculation for Laminar and Turbulent flow

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May 22, 2019, 07:37
Reynold's number calculation for Laminar and Turbulent flow
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Raza Javed
Join Date: Apr 2019
Location: Germany
Posts: 183
Rep Power: 7
Hello Everyone,

I have a question related to Reynold's number calculation.

As we know the relation for Reynold's number:

Re=(rho*u*L)/v

where

rho = density of the fluid (1000 in my case)

u = velocity of fluid (1e-3 in my case)

L=Diameter of pipe(2.5mm in my case)
v= kinematic Viscosity (959e-6 in my case)

Using the above values, my Reynolds number turns out to be less than 2300, it means that my flow will be Laminar.

But if due to some reasons, the velocity of fluid changes somewhere in the pipe, would it change the fluid flow from Laminar to Turbulent (because as per calculation using the above relation, if velocity increases more than 1.76m/s in my case, then the Re >4000, which means it is Turbulent flow)

I am attaching my geometry for your reference.

Thank you
Attached Images
 Screenshot from 2019-05-22 13-36-52.jpg (40.9 KB, 23 views)

 Tags laminar, reynolds number, turbulence