vortex structure in the impeller
 

Hello,my dear friends:
I doing the simulation about tip clearance flow in the impeller. I want to choose a appraach to the physical ieterpretation of the tip clearance flow in the impeller. I normalized helicity in CFX-Post. The normalized helicity defined as (Velocity dot Helcity)/(Magnitude (Velocity) * Magnitude (Vorticity)).How can I use the normalized helicity to present 3-D vortex structure ? I am grateful to your help!