Application of Energy Techniques to Propeller-Driven Airplanes

摘要

This thesis examines the validity of using the energy technique on propeller-driven aircraft during a climb analysis. It compares an accepted subsonic aircraft climb analysis method (pure potential energy increase) with an acceleration analysis procedure (pure kinetic energy increase) that has been a subject of criticism when used within a subsonic flight test program because of aircraft power limitations and flight test assumptions. The energy-state approximation was applied to a subsonic, propeller-driven aircraft using both a sawtooth climb analysis procedure and level acceleration method. Results showed that energy techniques, i.e. correlation between sawtooth and level acceleration methods, are a valuable support tool to the previously isolated potential energy (sawtooth climb) method. Data demonstrated a test time savings of approximately 7:1 with a variance in overall correlation that, although not within acceptable standards, is believed to be reducible with a more dedicated instrumentation selection. Data correlation suggested good agreement on best rate-of-climb speed determination. However, this should be an asset in reducing the time previously required for determination of excess thrust horsepower. Further testing, specifically with the level acceleration method, using higher resolution data acquisition equipment (with possibly an accelerometer) would fully demonstrate the extent of unaccountable losses and resulting disagreement between the two methods.