Analysis of free oscillations of a compressor blade of a gas turbine

Abstract

This article discusses about the free vibrations of the compressor blade of the gas turbine engine. The convergence of results is shown. A numerical analysis of frequency spectrum, vibration modes, relative stresses distribution and frequencies of perturbing harmonics where carried out. The blade vibration analysis shows the complexity of vibration modes and the fields of distribution of relative stress intensities. Effect of rotation mainly affects to the natural frequencies and far less to the waveform. The resonance condition is visually demonstrated  by the  Campbell vibration diagram, which plotted the frequency curves as a function of the blade speed and the harmonic frequencies of the disturbing forces. However, to determine the actual vibratory stress requires an assessment of the harmonic amplitudes of disturbing forces, which requires further research.