Module 2 :
Lecture 5 : Kolmogorov Hypothesis and Energy Cascade
 


Energy Cascade

The large eddies break down into smaller eddies. Smaller eddies break down into still smaller eddies, and so on

Big whorls have little whorls

Which feed on their velocity

And the little whorls have lesser whorls

And so on to viscosity

At very small scales, the viscous forces become dominant dissipate energy. Equilibrium distribution of energy is brought about.

The small scales can be estimated from the situation when the energy is dissipated into heat

Turbulent dissipation rate, , having the dimension

Kinematic viscosity, having the dimension