Simultaneous Estimation of Engine Deck and Drag Polar Based on Specific Excess Power Measurement

Abstract

© 2024, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.Most performance data reduction methods rely on the availability of a flight thrust deck. Nevertheless, for many reasons, such as industrial intellectual property, this information is not always available for the aircraft end user, or has prohibitive costs. For that reason, the ability to estimate an engine flight thrust deck based on flight data may be of special interest for flight test organizations or flight test schools. Thus, the objective of this work is to demonstrate a flight test method that enables the estimation of a reliable engine deck, using limited flight test instrumentation. The proposed method uses the specific excess power to estimate the thrust and drag balance. By combining level flight accelerations at constant altitudes and climb/descents at constant Mach numbers, using different thrust settings, it was possible to estimate the engine thrust for a combination of engine rotation speeds, altitudes, and airspeed. Using the method, it was also possible to estimate the drag polar at different Mach numbers.