Patent ID: 6010303
Filing Date: 2000-01-04
Classification: F04D,F05D

Abstract:
A method for generating a real-time signal indicative of an energy-type instability precursor in a turbofan engine having a plurality of blades spaced substantially equidistant from each other about a rotational axis, comprising the steps of:sensing periodically in real-time resonance waves associated with aerodynamic or aeromechanical resonance in a compressor portion of a turbofan engine and generating therefrom a real-time signal indicative of the energy of resonance;bandpassing the real-time signal within a predetermined range of frequencies associated with precursors to aerodynamic or aeromechanical instabilities in turbofan engines to form a bandpassed signal;squaring periodically in real time the magnitudes of the bandpassed signal to form a squared-magnitude signal;summing the magnitudes of the squares of the bandpassed signal to form an instability precursor signal indicative of imminent aerodynamic or aeromechanical instabilities; andemploying the real-time instability precursor signal to dampen or prevent the imminent instability from occurring.