Control of Oscillations in Jet Engines: From Fixing Problems to the Design of Dynamics

Dr. Andrzej Banaszuk, United Technologies Research Center

The talk will summarize the lessons learned during eight years of industrial research on mitigation of flow and structure oscillations in jet engines. We will advocate the need to change the role of control theory from fixing the detrimental dynamics using active control (with narrow focus on control algorithms) to the design for beneficial dynamics early in the design cycle. Particular case studies will include mitigation of thermoacoustic instabilities and turbomachinery flutter. We will show how the decisions on the control system architecture (sensor and actuator location) impact achievable level of suppression of oscillations (fundamental limitations of performance). We will also show how certain aspects of design of jet engines (symmetry)contribute to origin of detrimental oscillations and point out how dynamical systems and control theory methods can guide the design of the engines to prevent the oscillations.