Loads from Centrifugal Supercharger.

[xydrex]

I need to determine the axial & radial loads resulting from a centrifugal blower to facilitate appropriate bearing selection & arrangement. The books I found all focused on centrifugal pumps for liquids, I have not yet found one that deals with these issues for air. Can anyone point me to a good reference text or any other links that may have this info, & any other sources that advise on bearing arrangement in general for such blowers.
Thanks..