1. BTZ-Feb. 16, 2000 MITE NASA Glenn/Army Visitors February 16, 2000 MITE PROGRAM OVERVIEW MURI (Multidisciplinary University Research Initiative) on Intelligent Turbine Engines Ben T. Zinn School of Aerospace Engineering Sponsored by DoD-Army Research Office

2. BTZ-Feb. 16, 2000 MITE MITE Program Objectives Develop general control approaches sensors/actuators computational tools that will permit turbine engine manufacturers to improve the design process, performance, operability and safety of future gas turbines. Demonstrate developed technologies on small-scale experiments Transfer developed technologies to industry and government

3. BTZ-Feb. 16, 2000 MITE Compressor Control  Surge  Stall  Margins Control Issues Combustor Control  Stability  Ignition (relight, cold)  Temperature (pattern factor)  Combustor size  Efficiency and emissions Interactions

4. BTZ-Feb. 16, 2000 MITE Control theory for nonlinear systems Improved system models for control applications CFD/LES modeling of compressors/combustors Neural network hardware (chip design) High speed observers for system identification Sensors: MEMS high temperature applications, optical Synthetics jets for flow/combustion control Smart fuel injectors Enabling Technologies Being Developed

5. BTZ-Feb. 16, 2000 MITE Program Overview Start Date:November 1, 1995 Research Team:Eleven faculty members from 3 Schools (AE, ECE, ME) with expertise in controls, compressors, combustion, propulsion, fluid mechanics, diagnostics, sensors MEMS and neural nets. Facilities:Combustion, compressor, microelectronics and fluid mechanics laboratories

6. BTZ-Feb. 16, 2000 MITE MITE Research Team

7. BTZ-Feb. 16, 2000 MITE Compressor Control  Goal: reduce stall margin through active/passive control  Fundamental understanding of stall and surge dynamics through extensions to Moore-Greitzer model  lead to improved control models and approaches  Stall and surge control through bleed valve and fuel modulations using observations of precursor waves  Adaptive neural net/fuzzy logic control method being applied to several aerospace applications such as helicopter flight control, X-36, guided munitions

8. BTZ-Feb. 16, 2000 MITE Robustness, disturbance rejection, control saturation Nonlinear Control Theory Unified Robust Optimal Framework

9. BTZ-Feb. 16, 2000 MITE  Hierarchical switching control  Provides theoretical foundation for designing gain scheduled controllers  Guarantees stability over a wide range of system operating conditions Nonlinear Control Theory Hierarchical Control Architecture

10. BTZ-Feb. 16, 2000 MITE Computational Modeling  Develop computational (engineering) models for:  Investigation of control approaches  Development of control (system) models  Design aids  Approaches  Unsteady Navier-Stokes for compressor flows: validated for axial and centrifugal compressors  Large Eddy Simulations (LES) for combustor: reacting, two-phase (liquid fuel) systems

11. BTZ-Feb. 16, 2000 MITE Unsteady CFD of Centrifugal Compressor  DLR/AGARD: p r =4.7, 22360 RPM, 4 kg/s

12. BTZ-Feb. 16, 2000 MITE Unsteady CFD of Compressor Flows 0.04 R Inlet Casing 5° Rotation Axis Impeller R Inlet 3-6% injection by mass

13. BTZ-Feb. 16, 2000 MITE Controlled Mixing Objectives Fuel-Air Mixing  Reduce size  Improved off-design performance (low fuel/air rates): high altitude relight  Improve stability - lean blowout  Correct degraded performance Turbine Inlet Temperature Profile  Remove hot/cold spots (turbine lifetime)  Minimize cooling air needs

14. BTZ-Feb. 16, 2000 MITE Control of (Fuel) Jet Mixing Axial Forcing D = 1” U = 40 ft/s Re D = 19,000 U Main Jet with Actuators  Most approaches involve manipulation of large scale, vortical structures  directly affect “stirring,” weakly coupled to small-scale mixing  Synthetic jets allow direct control of both scales Synthetic Jet h = 0.02” f = 1200 Hz

15. BTZ-Feb. 16, 2000 MITE Fuel-Air Mixing Results Unforced9 on, no modulation9 on, pulse modulation Air ( f =0) Acetone ( f =1) U i /U o =4

16. BTZ-Feb. 16, 2000 MITE Pattern Factor Control Using Synthetic Jets No actuation With synthetic jets CC

17. BTZ-Feb. 16, 2000 MITE Air injected into liquid stream  Good atomization across wide flow range (turndown ratio)  Effective with low Insensitive to body acceleration (vs. effervescent methods )

18. BTZ-Feb. 16, 2000 MITE Wireless MEMS Sensors  Current system: 1000  F C(p,T) L  Develop fast (unsteady) sensors for high temperature enviroments  Wireless pressure (and temperature) sensors based on ceramic packaging technology  passive circuit element, no power supply: antenna readout