Apparatus and method of predicting aerodynamic and aeromechanical instabilities in turbofan engines
AssigneeUnited Technologies Corporation
InventorMatthew R. Feulner
Life of this patent
Estimating the term…
Abstract
A system and method is provided for generating a real-time signal indicative of an energy-type instability precursor in a turbofan engine. A sensor is positioned in a compressor portion of a turbofan engine for generating a real-time signal indicative of energy of aerodynamic or aeromechanical resonance waves generated in the compression system. The signal is bandpassed to generate a filtered signal within a predetermined range of frequencies indicative of a precursor to instability such as rotating stall, surge or flutter. The bandpassed signal is squared in magnitude and then lowpassed to generate an instability precursor signal used to prevent imminent aerodynamic or aeromechanical instability from occurring in the aerocompression system.
Claims13
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;
- and
- employing the real-time instability precursor signal to dampen or prevent the imminent instability from occurring.
A method for generating a real-time signal indicative of an energy-type instability precursor in a turbofan engine of an airplane or power plant, comprising the steps of:
- sensing in real-time resonance waves associated with aerodynamic or aeromechanical resonances 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 a magnitude of the bandpassed signal to form a squared-magnitude signal;
- lowpassing the squared-magnitude signal to form an instability precursor signal indicative of imminent aerodynamic or aeromechanical instabilities;
- and
- employing the real-time instability precursor signal to dampen or prevent the imminent instability from occurring.
A system 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, the system comprising:
- a sensor positioned in a compressor portion of a turbofan engine for sensing periodically resonance waves associated with aerodynamics and aeromechanics of fan blades in a compressor portion of a turbofan engine and generating therefrom a real-time signal, wherein the sensor detects pressure waves;
- a bandpass filter for periodically receiving the real-time signal at an input and for passing to an output a bandpass signal derived from the real-time signal within a predetermined bandpass range of frequencies associated with precursors to mechanical instabilities in turbofan engines;
- a multiplier circuit having two inputs each receiving the bandpassed signal for generating a squared-magnitude signal;
- and
- a lowpass filter receiving at an input the squared-magnitude signal to form an instability precursor signal indicative of a precursor to mechanical instability within a turbofan engine.
Dependencies are inferred from the claim text.