| Summary: | This is the second part of a two-part paper. It presents four case studies. The first case is the redesign of a transonic rotor (NASA rotor 67) at a post peak efficiency operating point. The second case is a redesign of a transonic compressor stage originally designed by DLR. The redesign is carried out at the stage peak efficiency point. The third and fourth cases look at the redesign of blade rows within a three-stage transonic test compressor that was originally designed by Siemens Industrial Turbomachinery Ltd known as the ATC compressor. Specifically the third case is a redesign of the IGV-rotor-stator configuration. It is carried out at two operating points: one is at the stage peak efficiency point; the other is at a lower stagnation pressure ratio choked flow point. Initially the redesign at the stage peak efficiency point produces considerable efficiency gain, but leads to noticeably reduced choked mass flow rate. The redesign at a near choked mass flow rate point, on the other hand, leads to considerable performance deterioration at operating points with lower mass flow rate, though the choked mass flow rate is even increased. Subsequently, a parallel multi-point approach has been implemented. Results show that a two-point design optimization avoids unacceptable performance deterioration at off design conditions. In the fourth case a redesign is applied across all 7 blade rows of the ATC compressor at the compressor design point. All these case studies are aimed to increase isentropic efficiency whilst meeting the specified constraints. Copyright © 2008 by ASME.
|
|---|