Fan Stall Detection System

Abstract

A system for detecting onset of a stall in a rotor is disclosed, the system comprising a sensor located on a static component spaced radially outwardly and apart from tips of a row of blades arranged circumferentially on the rotor wherein the sensor is capable of generating an input signal corresponding to a flow parameter at a location near the tip of a blade, a control system capable of generating a rotor speed signal, and a correlation processor capable of receiving the input signal and the rotor speed signal wherein the correlation processor generates a stability correlation signal.

1 . A system for detecting onset of a stall in a rotor, the system comprising:
 a sensor located on a static component spaced radially outwardly and apart from tips of a row of blades arranged circumferentially on the rotor wherein the sensor is capable of generating an input signal corresponding to a flow parameter at a location near the tip of a blade;   a control system capable of generating a rotor speed signal; and   a correlation processor capable of receiving the input signal and the rotor speed signal wherein the correlation processor generates a stability correlation signal.   
     
     
         2 . A system according to  claim 1  further comprising:
 a plurality of sensors arranged on the static component spaced radially outwardly and apart from tips of the row of blades.   
     
     
         3 . A system according to  claim 2  wherein the sensor is a pressure sensor. 
     
     
         4 . A system according to  claim 2  wherein the sensor is a pressure sensor capable of generating a pressure signal corresponding to the dynamic pressure at a location near the blade tip. 
     
     
         5 . A system according to  claim 1  further comprising:
 a plurality of sensors arranged circumferentially on the static component around an axis of rotation of the rotor and spaced radially outwardly and apart from tips of the row of blades.   
     
     
         6 . A system according to  claim 2  wherein the static component is a casing. 
     
     
         7 . A system according to  claim 2  wherein the static component is a shroud. 
     
     
         8 . A system according to  claim 1  wherein the rotor comprises a plurality of fan rotors. 
     
     
         9 . A system according to  claim 1  wherein the sensor is located at a location on the static structure corresponding to the mid-chord of a blade. 
     
     
         10 . A system according to  claim 1  wherein the sensor is located at a location on the static structure corresponding to the lead edge of a blade. 
     
     
         11 . A system for detecting onset of a stall in a fan rotor comprising:
 a pressure sensor located on a static component surrounding tips of a row of fan blades wherein the pressure sensor is capable of generating an input signal corresponding to the dynamic pressure at a location near the blade tip;   a control system capable of generating a fan rotor speed signal; and   a correlation processor capable of receiving the input signal and the fan speed signal wherein the correlation processor generates a stability correlation signal.   
     
     
         12 . A system according to  claim 11  further comprising a plurality of fan rotors wherein a plurality pressure sensors are located on the static component surrounding tips of a row of fan blades of at least two fan rotors. 
     
     
         13 . A system according to  claim 11  further comprising a plurality of sensors arranged circumferentially on the static component around an axis of rotation of the rotor and spaced radially outwardly and apart from tips of the row of fan blades. 
     
     
         14 . A system according to  claim 11  wherein a fan blade tip operates at a supersonic speed during the generation of the pressure signal. 
     
     
         15 . A system according to  claim 11  wherein the correlation processor receives the input signal from a plurality of pressure sensors and the rotor speed signal to generate a correlation signal. 
     
     
         16 . A system according to  claim 11  wherein the correlation processor generates a correlation signal based on the input signal from a plurality of pressure sensors and the rotor speed signal. 
     
     
         17 . A system according to  claim 11  wherein the correlation processor generates a correlation signal based on the input signal from pressure sensors located on the static component surrounding tips of a row of fan blades of at least two fan rotors. 
     
     
         18 . A system according to  claim 11  wherein the static component is a casing. 
     
     
         19 . A system according to  claim 11  wherein the static component is a shroud. 
     
     
         20 . A system according to  claim 11  wherein the sensor is located at a location on the static structure corresponding to the mid-chord of a fan blade. 
     
     
         21 . A system according to  claim 11  wherein the sensor is located at a location on the static structure corresponding to the leading edge of a fan blade.