Research Of The Exhaust Electrostatic Sensor Based On Electrostatic Induction

Exhaust electrostatic monitoring technology is a new monitoring technology of Aero-engine gas path component operating mode and failure, which provide prewarning information when Aero-engine gas path component occur performance degeneracy and failure.The exhaust electrostatic sensor is the core component part of exhaust electrostatic monitoring system, composed by sensitive probe and the signal processing module; it can detect the changes of exhaust charged particles which exhaust from engine tailpipe. The formation mechanism of charged particles, the composition and influencing factors of charge level are analyzed, and the exhaust electrostatic sensor which is the core components of exhaust electrostatic monitoring system that composition and spatial sensitivity characteristics are studies.This paper conducted the following research aspects: The structure type and the use of materials of sensor is selected for the complex work environment of engine nozzle, an exhaust electrostatic sensor is designed to meet the requirement of exhaust monitoring under high temperature. The sensitivity distribution of exhaust electrostatic sensor probe is hard to obtain by Analytical method and experimental method. Aiming at this problem, based on point charge principle the mathematic model of electrostatic field generated by a club-shaped probe is established. Numerical solution method based on finite element is proposed to obtain sensitivity distribution of the sensor probe. The distribution function of sensitivity is obtained by data fitting method, then the effect of structure parameters and material characteristics on the sensing fielding are explored detailedly; Aiming at problems of weak electrostatic induction signal detection, the noise sources of detection circuit are discussed and the relevant solutions are proposed, a signal processing circuit embedded in sensor is designed. The temporal frequency characteristic of the sensor output signal and influence factors are investigated theoretically.