Turbulence
1. Turbulence is a flow condition in which local speed and pressure change unpredictably as an average flow is maintained.
2. Turbulence – a phenomenon that consists in the fact that, as the flow rate of liquid or gas in the medium spontaneously formed numerous nonlinear fractal wave and conventional, linear sizes, without the presence of external, random, disturbing impact forces and/or their presence.
Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe.
The onset of turbulence can be predicted by the dimensionless Reynolds number, the ratio of kinetic energy to viscous damping in a fluid flow. However, turbulence has long resisted detailed physical analysis, and the interactions within turbulence create a very complex phenomenon. Richard Feynman has described turbulence as the most important unsolved problem in classical physics.
The turbulence intensity affects many fields, for examples fish ecology, air pollution and precipitation.
Google’s English dictionary by Oxford Languages https://languages.oup.com/google-dictionary-en/
Англійський словник Коллінза, https://www.collinsdictionary.com/
Britannica https://www.britannica.com/science/