Richard M. Murray
United Technologies Research Center
Nonlinear Dynamics and Control of Fluid with Applications to Turbomachinery
This talk will provide a survey of some of the nonlinear dynamics and control problems that arise in the context of turbomachinery, primarily motivated by gas turbine engines for propulsion and power. By making use of reduced order models and control-orineted nonlinear analysis techniques, substantial progress has been made in understanding and actively controlling fluid instabilities in these systems. Specific results include stabilization of rotating stall and surge in axial flow compression systems and control of combustion instabilties in lean, pre-mixed industrial power systems. Nonlinearity plays an integral role in both the dynamics and control of theses systems and non-equilibrium behavior (e.g., stable and unstable limit cycles) must be exploited. Analytical results on bifurcation control in the presence of magnitude and rate limits give insights into some of the fundamental performance limitations in active control of this class of fluid instabilities. Experimental results on a low speed, axial flow compressor and a full-scale industrial conbustion rig will be used to illustrate the combined role of dynamic modeling and analysis with active control technology.