Reynolds number

The Reynolds number is a dimensionless quantity in fluid mechanics that describes the ratio of inertial forces to viscous forces in a flow system.

The Reynolds number (Re) is used to characterize the flow behavior of a fluid and determine whether the flow is laminar, transitional, or turbulent.

At low Reynolds numbers, the flow is laminar, and the inertial forces do not dominate over the viscous forces. The flow is stable, and the velocity of individual fluid layers is uniform.
At high Reynolds numbers, the flow becomes turbulent, and the inertial forces dominate over the viscous forces. The flow is chaotic and swirling, and the velocity of the fluid layers varies significantly.

The Reynolds number is used in fluid mechanics to analyze and understand the flow behavior of liquids in pipes, channels, pumps, valves, and other flow systems. It is an important tool for the design and optimization of flow processes and systems.