how to improve mesh quality around sharp edge?
 

This is the tip of a nozzle. I have to generate the prism layer to get y+~1.
without prism, the overall mesh quality and skewness are really good.
however, after generating prisms, the quality got really poor.
I found most of worst mesh grids are around the tip of the nozzle.

Could any body tell me how to improve the quality?
If necessary, I can modify the sharp edge and make a round fillet.

Do you have access to Simon's Tip and tricks 2010? There are very useful hints.

It is always good idea to share project at earliest ;)