Computational and Experimental Studies of Model Fans for Advanced Turbofan Engines

The paper presents the results of aeromechanical design of a large-scale model stage for a high-efficient low-noise fan designed for an advanced civil geared turbofan engines with ultra-low rotational speeds of rotor blades (313.4 m/s), high flow specific capacity (up to 202 kg/m2/s) and high bypass ratio (13.5). Total pressure ratio in the bypass duct of the fan model stage is 1.38. To ensure the experimental studies, characteristics are calculated from choking to a surge line within a wide range of rotational speeds. For the studies of the experimental fan model (EFM), a design project is developed and used in manufacturing a fan stage with 0.7-m rotor diameter for tests at the C-3A acoustic test facility. The manufacturing technology for blades made of polymer composite materials (PCM) is of particular importance. Rotor blades of the geared fan model are made of PCM. The analysis of experimental data and their comparison with the computation results within the range of corrected rotational speeds from 0.325 to 1.0 are presented. At first, only gas-dynamic and strength characteristics of the stage are studied. The analysis shows a good agreement of calculated integral parameters with the experimental data. Acoustic performances of the EFM will be studied later on.