[maria_d]

Hello..
I am trying to make a simulation of an airflow with dispersed water particles around a cylinder and to calculate the collection efficiency coefficient for the cylinder surface in Ansys CFX .

I have successfully got the simulation solution (or so I suppose) but I do not now how to extract the collection efficiency coefficient and plot it's distribution along the circumference of the cylinder.

The formula for the collection efficiency coefficient is:
β =−(Vf.s*V.s*n)/(Vf.inf*V.inf)

where:

Vf.s = water volume fraction on surface
V.s = velocity of water on surface
n = normal vector outward the wall boundary (the cylinder)
V.inf = velocity of water in the unperturbed state(at the inlet I suppose
Vf.inf = water volume fraction in the unperturbed state



I have read almost every paper on this subject and a lot of tutorials and articles and documentation on building expressions in CFD-post but I just can't get it done.