CONTROL APPROACHES TO SOLUTION OF COMPRESSOR STALL

The control of compressor stall and surge is one of the most difficult problems confronting the control engineer today. Three modes of stall control are presented: (1) the scheduling, or open loop, control now in use on most gas turbine engines, (2) the closed loop control using compressor parameters which synthesize the stall boundary, and (3) the closed loop control using an incipient stall ‘sensor’. The use of a closed loop control which uses synthesizing stall parameters may partially solve some of the present problems, such as variations in physical properties of fuel. However, there is a great incentive to develop a means for detecting incipient stall and surge in order to aid in reducing the development time for future supersonic, high altitude gas turbine engines.