Digital computer simulation of the dynamic response of a twin-spool turbofan with mixed exhausts

The dynamic behaviour of gas turbines is of great practical importance, but unfortunately it cannot be investigated experimentally until late in the development programme when the mechanical integrity of the engine has been established. In the case of aero engines there is a requirement for fast engine accelerations and all engine transients must be achieved with complete safety. Thrust response rates must be guaranteed by the engine manufacturer at a very early stage and clearly it would be of great value to study engine transient behaviour at the design stage; this should lead to a significant saving in development time and cost by decreasing the amount of test bed running required.