Reynold's Experiment

REYNOLD’S EXPERIMENT

It was introduced by Osborne Reynolds (1842–1912), who popularized it’s use in 1883. In his 1883 paper Reynolds described the transition from laminar to turbulent flow in a classic experiment, in which he examined the behavior of water flow under different flow velocities using a small stream of dyed water introduced into the center of clear water flow in a larger pipe. The larger pipe was glass so the behavior of the layer of the dyed stream could be observed, and at the end of this pipe there was a flow control valve used to vary the water velocity inside the tube. When the velocity was low, the dyed layer remained distinct through the entire length of the large tube. When the velocity was increased, the layer broke up at a given point and diffused throughout the flu-id's area cross-section. The point which this happened was the transition point from laminar to turbulent flow. The ratio of inertia forces to viscous forces, the parameter obtained is called the Reynolds number (Re), in honor of Osborne Reynolds

where,
Re = Reynold’s number
V = velocity of fluid
D = diameter of pipe
μ = dynamic viscosity of fluid
ρ = density
With respect to Reynolds number: Re = 2300 transitional flow.

Laminar Flow (Re < 2300, only in pipe): Laminar flow may be described as an orderly pattern , i.e. in laminar flow the fluid moves in layer, or laminas, one layer sliding over an adjacent layer with only a molecular interchange of momentum. Such that the transverse exchange of momentum is insignificant.

Turbulent Flow (Re > 2300, only in pipe): The turbulent flow is a three-dimensional random phenomenon, exhibiting multiplicity of scales, possessing