The Reynolds (Re) number is the ratio of inertial forces to viscous forces and is a convenient parameter for predicting if a flow condition will be laminar or turbulent.
If Re is less than 2000, the flow is called Laminar, and if Re is greater than 4000, the flow is called turbulent.
Formula to calculate Reynolds number.
ρ = Fluid density
V = Fluid velocity
μ = Fluid viscosity
L = Diameter of the fluid.
Example:
Calculate the Reynolds number if a liquid of viscosity 0.5 Ns/m² and relative density of 400 Kg/m³ through a 0.01m pipe flows with a Velocity of 2m/s.
Therefore, the Reynold number is 16. Here, we notice that the value of Reynolds number is less than 2000, thus the flow of liquid is laminar.
