A flexible method for the off-design analysis of SST powerplant installations suitable for global optimization

This paper presents a flexible and relatively fast analytical method to carry out the off-design analysis of a powerplant installation for a supersonic transport aircraft (bypass engines). The procedure does not impose any constraints on the operating points of the turbines (like, for instance, requiring them to remain choked), except those corresponding to actual physical limitations, such as bounds on the compressor exit temperature and the turbine entry temperature. The result of the procedure is a single, closed-form expression that yields an off-design operating point of the engine at a given Mach number, altitude and low-pressure turbine pressure ratio.