3.43 Engine technologies
Engines must fulfill several requirements at different design points, like the aircraft Efficiency:
SCT-engines must be very efficient at supersonic and high subsonic cruise, and must provide sufficient thrust at take-off. transonic (low supersonic) acceleration and cruise.
To protect the atmosphere, pollution has to be minimized. Especially low NO,-bumers must be developed. This is even more stringent than for subsonic aircraft, because SCT fly higher and burn at higher temperatures during cruise.
Engine noise during take-off and landing must be comparable to subsonic aircraft (ICAO annex 16. chapter 3; FAR 36. stage 3). This requires large nozzle exit areas, comparable to subsonic aircraft of the same weight.
The multipoint capabilities of the engines are strongly related to the configuration selected For example thrust available during take-off and landing depends on engine bypass ratio, noise reduction by suppression or simply throttling down, possible integration of noise suppressors in the airframe etc. This influences engine weight, and thrust available and engine efficiency in the other design points. On the other hand, thrust required in the design points is determined by the configuration, mainly aerodynamic performance and weight.