"Jon Elson" wrote in message
ervers.com...

With 8" diameter rotors, your pressure differential per stage is going
to be WAY less than that. Your choice is to go to much larger rotors
or much higher RPM. Turboprop engines using centrifugal compressors
that size usually run around 80 thousand to 100 thousand RPM.
They probably do develop 3:1 compression per stage at those speeds.

With a well designed rotor you can get a maximum of 3:1


A great book I picked up on eBay is "Gas Turbine Theory" by
Cohen, Rogers and Saravanamuttoo. It has a bunch of VERY simple
procedures, at least for a theoretical book, for figuring these
things out. But, their numbers do assume some aerospace mettallurgy.
I think you can plug in the right factors for the materials at your
disposal, though.

Jon


Our compressor LP is 7 stage and delivers 120 psi ( at 4500 RPM) into a 3
stage HP (10,000 RPM) that outputs 312 psi at 40#/sec.
The motor is ratings are on a similar scale 7000V 690A 11,250HP.
Pat