[Julian121]

I would like to show tip leakage vortex core for a rotor with tip clearance.
I used streamline at a surface defined at 99% span corresponds to the halfway of tip clearance height but it shows all streamline coming over the tip clearance. Is there a way to show just the tip leakage vortex?
Should I use particle tracking for this purpose?

[ghorrocks]

Should I use particle tracking for this purpose?

You use particle tracking when you want to track particles, not when you want to visualise vorticies. So that is a no.

There are some additional variables in CFD-Post which can help in visualising vorticies. Have a look at the vortex core variables.

Your plane shows that all the flow at 99% span goes straight through and does not participate in the tip vortex. So try another % span. Also try seeding the streamlines at points just behind the tip where you think the vortex will be present. You just need to experiment with some seeding locations until you get it right.