How and why Reynolds number experiment is carried out?

How and why Reynolds number experiment is carried out?

The experiment was performed by injecting a thin stream of colored fluid of the same density of water into a long transparent water flowing tube. The Reynolds number is a function of many intangible fluid properties, such as flow velocity, fluid density, pipe diameter, and fluid viscosity.

How do you find the Reynolds number experimentally?

By measuring the mean bulk flow rates and calculating a value for the mean bulk speed of the fluid the Reynolds number (Re) can be determined. Using this experimental equipment we observed both laminar and turbulent flow, as confirmed through our calculated values of Re = 1100 300 and Re = 9400 700 respectively.

What is Reynolds number experiment?

The Osborne Reynolds experiment is used to display laminar and turbulent flows. During the experiment it is possible to observe the transition from laminar to turbulent flow after a limiting velocity. The Reynolds number is used to assess whether a flow is laminar or turbulent.

What are the important conclusions resulting from Reynolds experiment?

[1] concluded that Reynolds number has the effect of increasing axial velocity skin friction, axial velocity, normal velocity skin friction, and heat transfer rate both in the case of impermeable plate and porous plate.

What is the purpose of Reynolds number?

The purpose of the Reynolds number is to get some sense of the relationship in fluid flow between inertial forces (that is those that keep going by Newton’s first law – an object in motion remains in motion) and viscous forces, that is those that cause the fluid to come to a stop because of the viscosity of the fluid.

What is the significance of Reynolds number?

The Reynolds number, referred to as Re, is used to determine whether the fluid flow is laminar or turbulent. It is one of the main controlling parameters in all viscous flows where a numerical model is selected according to pre-calculated Reynolds number.

How does Reynolds number effect flow?

The Reynolds number (Re) helps predict flow patterns in different fluid flow situations. At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers flows tend to be turbulent. Reynolds numbers are an important dimensionless quantity in fluid mechanics.

What is the use of overflow pipe in Reynolds number experiment?

A fixed overflow pipe in the reservoir connects to a suitable drain. At the bottom of the test pipe is a valve which controls the flow rate through the pipe, without disturbing the flow. Students collect a known quantity of water in a measured time to find the flow rate.

What is Reynolds number and its physical significance?

This is proportional to the ratio of inertial forces and viscous forces (forces resistant to change and heavy and gluey forces) in a fluid flow. The Reynolds number is used to study fluids as they flow. The Reynolds number determines whether a fluid flow is laminar or turbulent.

How does the Reynolds number affect the flow?

As Re increases, the inertial force becomes relatively larger, and the flow destabilizes and becomes fully turbulent. The Reynolds experiment determines the critical Reynolds number for pipe flow at which laminar flow ( Re<2000 ) becomes transitional ( 2000<4000 ) and the transitional flow becomes turbulent ( Re>4000 ).

What do you need for the Reynolds number experiment?

The following equipment is required to perform the Reynolds number experiment: The F1-20 Reynolds demonstration apparatus, Stopwatch for timing the flow measurement, and Thermometer. 6. Equipment Description

What is the difference between low and high Reynolds numbers?

At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers flows tend to be turbulent. The turbulence results from differences in the fluid’s speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow ( eddy currents ).

What is the Reynolds number for a cylinder?

A vortex street around a cylinder. This can occur around cylinders and spheres, for any fluid, cylinder size and fluid speed, provided that it has a Reynolds number between roughly 40 and 1000. George Stokes introduced Reynolds numbers. Osborne Reynolds popularised the concept.