Reynolds from his experiments found that the nature of flow in a closed pipe depends upon the following factors:
REYNOLD'S NUMBER • Reynolds from his experiments found that the nature of flow in a closed pipe depends upon the following factors: (i) Diameter of the pipe (D), (ii) Density of the liquid (p), (iii) Viscosity of the liquid (μ), and (iv) Velocity of flow (V). • By combining the above variables, Reynolds determined a non-dimensional quantity equal to ρ V D / μ which is known as Reynolds number (Re). • Laminar and turbulent flows are characterised on the basis of Reynolds number. 1. If Reynolds number (Re) < 2000, then the flow in pipes is laminar. 2. If Reynolds number (Re) > 4000, then the flow in pipes is turbulent. 3. If Reynolds number is between 2000 and 4000, then the flow in pipes is unpredictable. • Since turbulent flow results in greater losses, therefore hydraulic systems should be designed to operate in the laminar flow region. • The turbulent flow can be converted into laminar flow by either reducing the velocity of liquid or by increasing the pipe diameter.
Hydraulics and Pneumatics: Unit I: Fluid Power Priniciples and Hydraulic Pumps : Tag: : Fluid Power Priniciples and Hydraulic Pumps - Hydraulics and Pneumatics - Reynold's Number
Hydraulics and Pneumatics
ME3492 4th semester Mechanical Dept | 2021 Regulation | 4th Semester Mechanical Dept 2021 Regulation