Sensor Requirements for Active Gas Turbine Engine Control

Abstract : This paper considers the potential benefits of active gas turbine engine control and briefly reviews a selection of the published material in the fields of detection and control of stall in axial flow turbomachines from the perspective of an instruumentation engineer. The use of a variety of sensors and mechanical installations is discussed and a specification for a pressure sensor which can he used to detect gas path instabilities in axial flow compressors is developed. Recent developments of Silicon-On-Insulator (SOI) piezoresistive pressure sensors for gas turbine research and development and basic aerodynamic research are described in this paper. Problems which can arise from use of these sensors in ultra harsh environments are discussed. The design of a new miniature dynamic pressure transducer capable of operating reliably under extreme environmental conditions - temperatures in excess of 480C (900F) and accelerations greater than 200g - is described in detail. The performance of such "leadless" pressure transducers is presented and indicates that ruggedised, high frequency, piezoresistive transducers are now feasible for use in the dynamic control of turbomachines.