Application of holographic interferometry for study rotor stator interaction in turbomachines

In article take up two examples application of holographic interferometry for investigation modes vibrations spinning bladed discs of engines and analysis vibrations taking into account rotor stator interaction.
In the first example blade vibration measurement on operating compressor were carried out to investigate the extent of blade excitation of impeller. Interesting responses of the radial blades to the excitation were obtained with the compressor with the cambered vane diffuser. Unusual and unexpected significant resonance peaks of blade were observable when rotating frequency is near 18000 rpm with maximum stress amplitudes. A vibration test at rest using holographic interferometry was carried out by taking an interferogram of the impeller with one diameter and circle.
In present paper for the first example was shown that strong impeller vibration excited by the diffuser vanes is due to interaction between impeller and diffuser vanes and spinning impeller oscillated with mode one diameter and circle.
In the second example vibrations wheel of turbine was investigated on holographic test stand and during spinning test. At work turbine wheel consisting of stage was find out that dangerous stresses with frequency about 8000 Hz arise from the action of 28 harmonic. At investigation of this wheel on the holographic stand was find mode with 7 diameters on the frequency 7893 Hz.
Strong turbine vibration excited stator vines is due to interaction between turbine wheel and stator vines. As a result spinning turbine wheel oscillated with mode 7 diameters.