Flight Assessment of the Onboard Propulsion System Model for the Performance Seeking Control Algorithm on an F-15 Aircraft

Orme, John S. and Schkolnik, Gerard S. (1995) Flight Assessment of the Onboard Propulsion System Model for the Performance Seeking Control Algorithm on an F-15 Aircraft. Technical Report NASA TM-4705, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

Performance Seeking Control (PSC), an onboard, adaptive, real-time optimization algorithm, relies upon an onboard propulsion system model. Flight results illustrated propulsion system performance improvements as calculated by the model. These improvements were subject to uncertainty arising from modeling error. Thus to quantify uncertainty in the PSC performance improvements, modeling accuracy must be assessed. A flight test approach to verify PSC-predicted increases in thrust (FNP) and absolute levels of fan stall margin is developed and applied to flight test data. Application of the excess thrust technique shows that increases of FNP agree to within 3 percent of full-scale measurements for most conditions. Accuracy to these levels is significant because uncertainty bands may now be applied to the performance improvements provided by PSC. Assessment of PSC fan stall margin modeling accuracy was completed with analysis of in-flight stall tests. Results indicate that the model overestimates the stall margin by between 5 to 10 percent. Because PSC achieves performance gains by using available stall margin, this overestimation may represent performance improvements to be recovered with increased modeling accuracy. Assessment of thrust and stall margin modeling accuracy provides a critical piece for a comprehensive understanding of PSC’s capabilities and limitations.

EPrint Type:	NASA Technical Memorandum
Keywords:	Airbreathing engines (aircraft), Aircraft engine testing, Aircraft propulsion systems, Engine control systems, Flight tests, Turbofan engines
Subjects:	(01 - 09) Aeronautics: (07) Aircraft Propulsion And Power (01 - 09) Aeronautics: (05) Aircraft Design, Testing And Performance Aircraft/Project: F-15 PSC
ID Code:	226
Deposited On:	19 July 2004
Additional Information:	20 pages. Presented as AIAA 95-2361 at the 31st AIAA/ASME/SAE/ASEE Joint Propulsion Conference, San Diego, California, July 10–12, 1995.