Particle impact angle and erosion rate in 90 degree pipe elbow

Hi,

I've modelled a 90 degree pipe elbow carrying oil with a k-omega turbulent model. I've computed the turbulent flow study and then ran a particle tracing module afterwards.
I'm currently trying to post-process my particle trajectories and find their impact angle on the pipe wall as well as their erosion rate. Is there a way I can do this on COMSOL 4.4? I'm kind of new to this, sorry.

Thanks.