Measurement Of Aerodynamically Induced Blade Distortion On A Shrouded Counter-Rotating Prop-Fan
J. Klinner (1), M. Schroll (1), T. Lengyel-Kampmann (2), J. Belz (3), F. Eichner (3), P. Winkelmann (4), C. Willert (1)
(1) Institute of Propulsion Technology (Measurement Techniques), German Aerospace Center (DLR), Köln, Germany
(2) Institute of Propulsion Technology (Fan and Compressor), German Aerospace Center (DLR), Köln, Germany
(3) Institute of Aeroelastics (Aeroelastic Experiments), German Aerospace Center (DLR), Göttingen, Germany
(4) Institute of Structures and Design (Component Design and Manufacturing Technologies), German Aerospace Center (DLR), Stuttgart, Germany
Blade deformation on a 1 m diameter composite fan rotor is measured simultaneously using stereoscopic image pattern correlation technique (IPCT) and blade-tip imaging. Absolute referencing of the blades is made possible by simultaneously tracking a marker on the hub using a fourth camera. Illumination is provided by microsecond pulses of high-power LEDs. Rise and fall time in the 100 ns regime are achieved using a self-designed high-current drive circuit. A high-speed microcontroller provides accurate, speed-independent angular delays to enable phase-locked triggering of cameras and LEDs. Mean and RMS deformation of the blade are acquired for different aerodynamic loading conditions induced by imposing a non-uniformity upstream of the rotor aimed at mimicking boundary layer ingestion.