Abstract
The objective of this study was to understand the theory behind turbofan electronic engine controllers (EECs) and to develop a Simulink based controller with stall margin limits, which was then used to build a simple 1-D cruise controller for a Boeing 747. The turbofan model used was the JT9D Pratt & Whitney engine in T-MATS with an attached βambientβ block to input altitude, Mach, and πΉπ΄π . Holding altitude at 35000 ft, the πΉπ΄π controller stall lower and higher limit maps were obtained from the 6% LPC and 15% HPC stall margins at steady state for 0.83-0.85 Mach and 2000-4000 π1 RPM. P and I gain schedules were obtained for the same conditions using a first-order model fit through step πΉπ΄π inputs, as other methods failed to linearize the system. The resulting controller was compared to the example controller given in T-MATS, showing an extended range of operating conditions and stall safety. The system was then fitted to a point-mass 1-D model for a cruise controller, and tested for wind gusts of 73 ft/s . The system showed stability and a settling time of around a minute.
Document Type
Final Report
Class Name
Mechanical Engineering and Material Sciences Independent Study
Language
English (en)
Date of Submission
12-12-2025
Recommended Citation
Torres, Ian, "PI Gain Scheduling and Stall Margin Protection for a JT9D Turbofan Engine Using T-MATS" (2025). Mechanical Engineering and Materials Science Independent Study. 318.
https://openscholarship.wustl.edu/mems500/318
Data gathered and PI scheduling tables