Effect of Blade Reference Design Variations on the Morphing Capability of a Shape-Adaptive Fan Rotor

By integrating piezoceramic Macro-Fiber-Composite (MFC) actuators into the blading of a fan rotor, a simultaneous morphing of the blade twist and turning can be achieved.While operating under off-design flow conditions the piezoceramic actuation allows to reduce flow incidence and deviation.With the overall goal to increase engine off-design efficiency, while maintaining a sufficient surge margin, this research aims to investigate the influence of blade reference shape variations on the morphing potential of a scaled fan rotor.An aerodynamic design methodology including a streamline curvature calculation is therefore coupled with structural morphing simulations.To quantify the impact of reference design variations on the blade's deformability a Design of Experiment is conducted, resulting in the investigation of different axial compressor designs, ranging from high hub-to-tip ratio compressor rotors to scaled Ultra-High-Bypass-Ratio (UHBR) fan blading.Finally, a UHBR fan design for a test rig application is selected and its morphing behavior is further investigated through quasi 3D (Q3D) simulations for representative tip section designs. METHODOLOGYAerodynamic pre-design: The derivation of the main dimensions is based on a minimum number of design parameters to reduce the DoE parameter space.The leading edge hub radius is selected according to the test rig dimensions and the scaled UHBR CA3ViAR design [9].With a hub-to-tip ratio of ht = 0.26 this fan design defines the maximum blade height within this investigation.To determine the blade length of each design, the hub-to-tip ratio ht is selected as the first DoE parameter.