N+3 and N+4 Generation Aeropropulsion Engine Combustors: Part 6: Operating Conditions, Target Goals and Lifted Jets

This paper summarizes academically simulated takeoff and cruise operating conditions for the N+3 and N+4 generation combustion systems and comparison likewise with the N and N+1 generation aeroengines in addition to GE9X and RB3025, potential engines introduced as marketing campaign start for the next upgrade of the B777. The technological challenges are summarized in order to meet very demanding NOx, CO and HC emissions goals without adversely impacting other design requirements that have generally been taken for granted for the rich-dome aeroengines. Technology assessments follow for several approaches including axially staged combustors with lifted LDI JIC compared to late lean concepts currently being followed by the power generation OEM’s. Premix and LDI approaches involving the use of variable geometry actuations are evaluated in addition to past and ongoing activities for developing several promising LDI concepts along with status on modeling capabilities that could be used for extending to axially staged micro LDI jets to be discussed in future publications.