If we examine the turbulent field of a forced vortex or a free vortex through a "magnifier", we can see the many scales of eddies existing among the vortex. I have a question: There is a Rankine combined vortex which includes an innner forced vortex and an outer free vortex. I want to know which is the larger about the scales of turbulent eddies among the two parts of the Rankine vortex. Please give me some advice to help me understand this question.

Thank you in advance.

LCW

The accurate method i guess is to plot the spectrum of the signal. Then you can see in the frequency domain which frequency is the strongest, if you defined what is 'stronger' or 'larger'.

Thank you first, yuan For this tipical flow, are there any theoretical method to analysis turbulent eddies scales?