Image Based Propeller Deformation Measurements on the Piaggio P180

Abstract

One of the most challenging tasks of the AIM project was to measure the deformation of a fast revolving propeller blade during flight by using the QVT (Quantitative Video Technique) and the IPCT (Image Pattern Correlation Technique). In order to be able to perform such a measurement, Piaggio and DLR worked together closely to solve the major problems to record images of the blade in a high quality to be processed with IPCT. Where to install the camera(s), how to illuminate the blade and how to trigger the camera and consequently the illumination device, were important questions to be answered before the test. The blade deformation measurement by itself was already a demanding target, but in order to give more value to such an activity one more step forward was also planned consisting in the evaluation of the possibility to investigate the effects of the exhaust impinging on the blade in terms of performance lost. Therefore, the recording system was designed so that it was possible to take recordings with a freely adjustable phase angle. Due to present problems with the triggering system it was not possible to make this evaluation. Nevertheless, in-flight propeller blade deformation measurements have been performed for one phase angle and for different flight conditions. In this contribution, the measurement task and the measurement setup are described briefly followed by the results of the performed ground tests and the executed flight tests.