Innovative approaches for reducing CO₂ emissions of aviation engines part 3: Advanced Brayton cycle optimization

Innovative approaches for significantly reducing the aviation Greenhouse Gas (GHG) emission need to be evaluated based on simple calculation methodology, viz. Numerical Propulsion System Simulation (NPSS)^1-3 that can be easily and reliably executed by an academic research group with guidance provided by a panel of experts from industry, FAA, NASA, DOE and DOD. Part 1 paper describes a list of the proposed advanced Brayton cycles for undertaking an extensive study under the FAA program. Part 2 shows that good agreement was achieved between the NPSS calculations and engine data for several engines, including the aero-engines CFM56, CF6-80C, GE90, and industrial engines LM6000 and LMS100 with and without recuperation. In the present paper, the same methodology is extended to NASA N+1 Advanced Geared Turbo Fan (AGTF) engine to further optimize the simple Brayton cycle with the N+3 component performance parameters. Further potential for reduction in CO₂ is shown by analyzing inter-cooled (IC), recuperated (R), and combined inter-cooled and recuperated (IRC) Brayton cycles.