Question

Consider the turbulent structure of thin shear layers. Which of these statements is correct?

(a) The rates of change of the flow variables are very high in every direction

(b) Flow variables do not vary much in any direction

(c) The rates of change of the flow variables in the cross-sectional direction are smaller than that of the flow direction

(d) The rates of change of the flow variables in the flow direction are smaller than that of the cross-sectional direction

The question was asked in an interview for job.

My enquiry is from Turbulence Modelling topic in section Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Right choice is (d) The rates of change of the flow variables in the flow direction are smaller than that of the cross-sectional direction

The explanation: Considering turbulence in thin shear layers, large variations are concentrated in thin regions. The variables do not change much in the flow direction. But, the rates of change in the cross-sectional direction are more.