Impact of Shape-Adaptive Fan Blading on the Performance of a Turbofan Engine

Within the Cluster of Excellence for Sustainable and Energy-Efficient Aviation (SE²A), technological advances to reduce carbon emissions of current propulsion architectures are investigated. In order to enhance the efficiency of the fan and compressor components of a turbofan engine during off-design operation, shape-adaptive fan and compressor blading is considered. This investigation introduces shape-adaptive blading for the fan stage of a V2500-A1 high-bypass turbofan engine, operated on Airbus A320 single-isle civil transport aircraft. Integrating piezoelectric actuators into the fan rotor blading allows varying the rotor twist and camber upon actuation. Special emphasis lies on an improvement of part-load operation, where lower efficiencies are expected and the surge-margin becomes more critical. During flight phases where the fan operates well outside its aerodynamic design point, a variable fan rotor shape allows reducing flow incidence and deviation. Especially during climb, where atmospheric conditions and engine thrust change with altitude, an improvement is shown. To assess the shape-morphing effects on the chosen aircraft configuration, previous morphing results are generalised and applied to the performance maps of the fan of the V2500-A1 turbofan engine. Within this investigation, two morphing configurations are considered and analysed on a whole mission-basis for three different flight scenarios. The morphing effect on the turbofan engine performance is quantified by combining structural morphing simulations with CFD simulations and a thermodynamic turbofan engine performance calculation tool. Special emphasis thereby lies on the mission specific fuel consumption (SFC) and the feasible fuel saving through introducing shape-adaptive fan blading. Results indicate, that small variations in blade angle already show an effect in SFC and motivate for future investigation of flight-phase optimised morphing strategies and application of the method to modern turbofan engines.