Estimation of Vibrational State of Mistimed Blade Assemblies of Turbomachinery Rotor Wheels

摘要

On the basis of the results of the investigations the influence of the parameters of elastic-dissipative coupling of subsystems on vibrations of a pair of shrouded blades and a shrouded blade assembly with violated symmetry has been established. It is shown that the formation of the amplitude-frequency characteristics and of the distributions of resonant vibration amplitudes depends on the correlation of the elastic and dissipative coupling parameters. Experimental and numerical studies of the vibration of a pair of shrouded blades have been performed for the determination of specific features of the influence of the parameters of elastic-dissipative coupling on the vibration of a shrouded blade assembly. The possibility of the generation of dangerous antiphase vibrations under which the level of the blade vibration stresses is considerably higher than that under inphase vibrations and depends on the parameters of their dissipative coupling and frequency mistiming has been established. The results of the investigations performed show the possibility of decreasing both the vibration stress level and the scatter of resonant vibration amplitudes of shrouded blade assemblies by the right choice of the parameters of elastic-dissipative coupling of the blades.