Speckle interferometry setup for studying the frequencies and modes of vibrations of turbo-machine rotor wheels

Abstract

During operation, the blades and disks of the turbo-machine rotor wheels suffer severe vibrations. To prevent resonant destruction of these parts, detuning from potential resonances is performed at the design and development stages. In order to do this, the natural frequencies and vibration modes are preliminarily determined, and it is often necessary to use experimental research methods. Speckle interferometry methods are preferred due to their high information content, panoramic view provided, and relatively low cost. Within the research, we developed a speckle interferometry setup, which makes it possible to record the modes of vibration of the disk and each blade of the rotor wheel assembly. The study describes the modes of vibrations of the compressor 5-stage rotor wheel and compares the frequencies and modes of vibrations of the blades in the wheel with the vibrations of a single isolated blade. The results obtained with this setup can be used to analyze strain gauge data, study mistuning of the rotor wheel, and to verify the numerical model.