Negulescu, C., "Airbus AI-PX7 CROR Design Features and Aerodynamics," SAE Int. J. Aerosp. 6(2):626-642, 2013, doi:10.4271/2013-01-2245.
The renewed interest in the fuel efficient and low CO2 emission CROR (contra-rotating open rotor) propulsion system for future commercial aircrafts has recently led to a series of isolated and installed CROR wind tunnel test campaigns performed in close collaboration between Airbus and the engine manufacturers. These tests aim at better understanding the potentials and limitations of the CROR configuration, as well as at generating reference data for the development and calibration of numerical tools for both industry and research centers. One of these tested CROR concepts is the AI-PX7 CROR propeller designed by Airbus.In this context, this paper presents multidisciplinary design features of modern high-speed contra-rotating propellers for commercial aircrafts. The influence of main CROR design parameters like blade number, propeller tip speed, rotor diameter, etc. on the propeller aerodynamics, acoustics and structures is described. Moreover, CROR blade shapes aerodynamic, acoustic and structural design considerations, like blade loading and blade sweep distributions are exposed.Finally, the design of the Airbus AI-PX7 CROR propeller is presented, as well as a steady-state and unsteady CFD analysis of the AI-PX7 CROR propeller aerodynamics.