WP 3 Objectives
Improvement of IPCT and Marker based techniques for propeller deformation measurements.
Development of a QVT setup for 360° propeller deformation measurements.
Improvement of installation, calibration and post-processing.
Flight vibration test performed by strain gauges for comparison.
WP 3 Deformation Measurements on Propeller Blades
Like shown in former projects, the combination of QVT and IPCT creates a useful tool to measure the shape of a propeller blade on the running propeller in-flight in a non-intrusive way. As the performed measurements had been done with cameras in the fix frame only a cut out of the propeller disc can be observed. The aim of WP 3 is to improve the QVT setup to be able to measure the complete revolution of the propeller blade (360°) with one camera system and to demonstrate the possibilities of the techniques in an industrial environment. Furthermore an optimization of the post processing is realized. Therefore the IPCT processing will be improved and marker based techniques, that could be sufficient, if only the angle of attack on discrete chords is needed, are also be evaluated.
Task 3.1. Improvement of IPCT and Marker based techniques toward industrial application
In the first step the results of the former propeller testing using optical measurement techniques are reviewed and evaluated by AP, DLR and EVE in order to identify the major problems to be solved. Starting with the identified problems and challenges, the single parts of the optical deformation measurement system (cameras, data acquisition, camera adjustment, camera calibration, illumination, data processing) is optimized for 360° propeller blade deformation measurements and prerequisites for a design of an optical 360° propeller blade deformation measurement system is created.
Task 3.2. Development of a setup for 360° propeller blade deformation measurements
Improvements from Task 3.1 are applied to design and realize an optimized setup for optical 360° propeller deformation measurements. AP, DLR and EVE do cooperate to create a useful measurement setup to record images of one propeller blade for the complete revolution that can be processed with IPCT or a marker based technique. Furthermore one blade is equipped with a random dot pattern and markers to enable the application of the techniques. To verify the new optical measurement technique a comparison with results of a classical measurement technique is performed.
Task 3.3. Flight test with 360° propeller blade deformation measurement system
The optical measurement system developed in task 3.2 is installed on the Evektor VUT100 Cobra and completed by an installed comparative measuring system. After successful installation a ground test is performed in order to verify the setup. If the setup gets the permit to fly a flight test on propeller deformation with the Evektor VUT100 Cobra will be conducted.
The data processing of both the images and the data of the comparative data will be performed in cooperation of DLR, AP and EVE.
Finally the applied optical measurement technique will be assessed with respect to practical industrial applicability.