University of Minnesota
Aerospace Engineering and Mechanics
Spring 1997 Seminar Series


Dynamics and Control of Resonant Surge/Stall Interactions in Compressor Models



Dr. Brianno Coller
California Institute of Technology

Abstract

In axial flow compressors there are two primary modes of instability: axisymmetric flow oscillations (surge), and asymmetric traveling wave disturbances (rotating stall). Since the occurrence of either during normal operation of jet aircraft engines could likely lead to catastrophic consequences, aeroengines are typically over-designed to obviate such possibilities.

Recent efforts, via active control, to suppress the instabilities and allow for more efficient designs closer to the stall/surge boundary have achieved only modest success. Difficulty arises when both modes are nearly critical, leading to complex interactions between the two types of behavior. In this talk, I present some work in progress on understanding these interactions from a dynamical systems viewpoint. In the analysis, we uncover a (quasi-) global resonant structure that can be exploited for control purposes. New challenges concerning the practical application of dynamical systems techniques to engineering systems emerge as well.


Friday, April 11, 1997
209 Akerman Hall
2:30 p.m. - 3:30 p.m.


Refreshments served after each seminar in 227 AKERMAN HALL .
Disability accommodations provided upon request.
Contact Leslie Petrus : Secretarial Assistant, (612) 625-8000.