Experimental Investigation of Methods for Improving the Dynamic Response of a Twin-Spool Turbojet Engine

This paper describes experimental tests carried out on a twin-spool turbojet to confirm earlier simulator predictions of methods of improving the dynamic response. The engine was controlled by a digital computer, permitting ready changes of control schedules. It was verified that dynamic response could be improved by trading HP surge margin for LP surge margin by suitable variation of the nozzle area. Operating trajectories were obtained on both compressor characteristics during both accelerations and decelerations and excellent agreement with simulator results was obtained.