Question

The kinematic turbulent viscosity is __________

(a) equal to the product of turbulent length and time scales

(b) equal to the product of turbulent length and velocity scales

(c) proportional to the product of turbulent length and velocity scales

(d) proportional to the product of turbulent length and time scales

This question was addressed to me in homework.

This question is from Turbulent Viscosity topic in section Turbulence Modelling of Computational Fluid Dynamics

Answer 1

The correct choice is (c) proportional to the product of turbulent length and velocity scales

Explanation: By using dimensional analysis, the relationship between kinematic turbulent viscosity, turbulent length and time scales can be established using the dimensional analysis. It can be expressed as

νt∝vl

Where,

νt →  Kinematic turbulent viscosity.

v →  Turbulent velocity scale.

l →  Turbulent length scale.