Question

_____________ are called the inertial sub-range of turbulence.

(a) Kolmogorov micro-scale

(b) Small scale eddies

(c) Intermediate scale eddies

(d) Large scale eddies

The question was posed to me in my homework.

This question is from Turbulence Modelling topic in portion Turbulence Modelling of Computational Fluid Dynamics

Answer 1

The correct answer is:

(c) Intermediate scale eddies

Explanation:

In turbulence theory, the inertial sub-range refers to a range of turbulence scales (or eddies) where the effects of viscosity are negligible and the inertial forces dominate. These scales lie between the large-scale energy-containing eddies and the small-scale dissipative eddies.

• Large scale eddies are the energy-containing scales that primarily determine the flow structure, but they are not part of the inertial sub-range.
• Small scale eddies are the viscous dissipation scales where energy is dissipated due to viscosity, and they are also not part of the inertial sub-range.
• Intermediate scale eddies, or the inertial sub-range, are where turbulence transitions between large-scale and small-scale behavior. This is the region where the Kolmogorov similarity theory applies, and energy cascades from large to small scales without significant viscous dissipation.

Correct Answer: (c) Intermediate scale eddies