PERFORMANCE CORRECTION MODELS FOR ADVANCED TURBOFAN ENGINES.

Advanced turbofan engines airflow and fan operating lines are controlled in order to optimize performance while maintaining adequate stability margin. Consequently, controls are configured to vary scheduled parameter values throughout the flight envelope. This paper investigates the effects that control-related changes have on the utility of several possible performance correction models. Performance correction models are used to infer performance at conditions other than those tested to determine specification compliance and for standardization of flight test data. Models now used in industry plus ones developed by the authors are examined systematically for sensitivity to errors associated with changes in control-scheduled, mode, trim level, and engine quality.