What is the Reynolds Number that indicates critical velocity in a domestic water system?

The Reynolds Number represents the ratio of inertial forces to viscous forces within a fluid flow and is crucial in determining whether the flow is laminar or turbulent. In the context of plumbing systems, particularly in domestic water systems, a Reynolds Number around 2,100 signifies the transition from laminar to turbulent flow.

When the flow is laminar (Reynolds Number less than 2,100), the fluid moves in parallel layers with minimal mixing. However, as the Reynolds Number exceeds this critical value, the flow begins to become turbulent, characterized by chaotic fluid movement. Turbulent flow is essential in plumbing systems for efficient transport of water, as it enhances mixing and reduces pressure losses associated with laminar flow.

Given this understanding, a Reynolds Number of 2,100 is recognized as the threshold indicating critical velocity, where the nature of flow significantly impacts the design and performance of plumbing systems.