Simple question

Question

The Reynolds number Re=pvr/n is useful for characterization of different flows, if the Reynolds number is 875, then the flow condition of the water in a long tube is _?

A) Turbelence flow;

B) Unsteady flow;

C) laminar flow;

D) none of the above

Answer 1

 

Re = ρvD/μ

 

ρ = density of fluid

v = speed of flow in pipe

μ = viscosity of fluid

D = diameter of pipe

 

For fully developed flow in a pipe, laminar flow occurs when Re < 2300, and turbulent flow occurs when Re > 2600.  If Re = 875, then you are in the laminar flow region, which is answer (C).