Question { 7547 }

How do we MEASURE OR CALCULATE VELOCITY used to calculate
REYNOLDS NUMBER??

Answer

REYNOLD NUMBER : It means rate of flow.
Re = p VD/u
Where
Re = Reynolds Number, v = Velocity of flow in m/s, d =
diameter of pipe in m, p = density of fluid in Kg / M³,, u
= Viscosity of fluid.
Turbulent or laminar flow is determined by the
dimensionless Reynolds Number.
The Reynolds number is important in analyzing any type of
flow when there is substantial velocity gradient (i.e.,
shear.) It indicates the relative significance of the
viscous effect compared to the inertia effect. The Reynolds
number is proportional to inertial force divided by viscous
force.
• laminar when Re < 2300
• transient when 2300 < Re < 4000
• turbulent when 4000 < Re