Calculate Reynold's number, if the kinematic viscosity of water is 0.01 × 10^-4 m²/sec, flowing through a pipe of diameter 200 mm with a velocity of 5 m/s.

Concept:

Reynolds Number Re is defined as the ratio of the Inertia force to viscous force.

Inertia force (Fi) = mass × acceleration

Viscous force (Fv) = shear stress × area 

Reynolds Number (Re) = 

we know kinematic viscosity ν = μ /ρ 

 For circular pipe 

 ∴ Re = VD/ν

Calculation: 

 Given, V = 5 m/s, diameter D = 200 mm = 0.2 m, ν = 0.01 stoke = 0.01 × 10-4 m2/sec

 Re = (5 × 0.2) /(1 × 10-6 )

 R_e = 1 × 106