Unified classification and characterization of axial turbomachines and propellers

Reaching the mid/long-term air transport emission reduction goals imposed by both European and American standards impose increasing the propulsive systems’ adaptability to various operating conditions, in order to maximize the aircraft overall efficiency all along the flight mission. This implies the enlargement of the design space of propulsive systems such that it can even be operated equally as a compressor or turbine, which leads to rethink the paradigm of designing turbomachines. The continuity in the definition and characterization of different types of turbomachines should be restored which is proposed through this contribution. Analytical relationships allowing to switch between compressor map, propeller map and map are developed. To minimize the inputs of the maps’ conversion relations, a methodology to extract mean flow features from any characterization map is presented, namely the rotor outlet relative flow angle and mean streamline radius. The application of the characterization maps’ conversion relations on a turbofan’s single-stage axial fan and on a propeller allowed their validation through the physical coherence of the results. The flow features extraction methodology also showed very satisfying results with comparison to experiments. Eventually, the ability of the formalism as a powerful performance analysis tool for all kind of turbomachines is stressed out, which makes it the best candidate for the unified treatment of turbomachines.