3.1. Design
To start design process, designer should define some com- pressor specifications:
A. First stage’s hub-tip ratio.
B. Value of increment of hub-tip ratio stage by stage (IR).
C. The safe blades tip speed for first stage to determine maxi- mum allowable ratio of Eq. (3).
D. Blading type, to determine velocities distribution along the blades.
E. Annulus shape to form blading.