Turbulence definition

Short definition of Turbulence definition
A brief description of turbulence. There is no formal definition of turbulence. Instead, it is described as a syndrome with key characteristics, which together, distinguish it from non-turbulent fluid motions.

This is the common definition for Turbulence definition, but other definitions maybe discussed within the wiki.

The key characteristics of turbulence are (Tennekes and Lumley, 1989);

• The flow is chaotic, or highly irregular, or random.
• The flow is rotational – it has three-dimensional vorticity.
• The flow is dissipative – kinetic energy is irreversibly lost through friction.
• The flow is diffusive – causing rapid mixing of fluid properties such as momentum, heat, and other scalar properties.
• The flow is non-linear and transports energy from large-scale eddies to small-scale eddies.
• The flow has a high Reynolds number.
• The flow is a continuum – the size of the smallest eddies is still many factors of 10 larger than any molecular length scale.

Turbulence is a characteristic of the flow and not the fluid. There are non-turbulent flows that have some but not all of the above-listed characteristics. For example, surface wave can be highly irregular but the motions induced by surface gravity waves are irrotational.