Propeller Design Point Calculation Method for Comparing Turbofan/Propfan Engine Performance

This paper presents a method to calculate the design point performance of both single rotation and dual contra-rotation propellers. Major propeller variables such as, power loading (shaft horsepower/prop diameter²), propeller efficiency (Prop Thrust × Acft Veloc/shaft horsepower), propeller tip speed and propeller adiabatic compression efficiency are accounted for and correlated. The resulting propeller performance is then combined with given shaft power producer (engine) performance to yield propfan engine performance. The performance trades between power loading, propeller efficiency, propeller tip speed and propeller adiabatic compression efficiency are presented. Resulting performance, with a given engine, are presented in the form of Figs 7 and 8 for both single and dual contra-rotation propellers. These engine performances can then be compared to advanced turbofan engines that utilize identical technology shaft power producer engines.