N+3 AND N+4 GENERATION AEROPROPULSION ENGINE COMBUSTORS: PART 1: LARGE ENGINES' EMISSIONS

摘要

A comprehensive assessment of emissions characteristics of the 1st, N and N+1 generation rich-dome combustion products has been done to identify the lowest emissions products. Focus of this paper is on the large rich-dome engines with its potential application for the (N+3) and (N+4) mixers with inspirational target takeoff NOxEI of 5 at 55 OPR. A total of ten engine models of the 1st generation were selected in addition to eight recently certified large engines. After evaluating several choices for conducting comparative assessment, the following three expressions were proposed for average takeoff NOxEI, idle COEI and HCEI entitlements, respectively: NOxEI_L = 0.0288 × OPR~(1.991) Idle COEI_L =815.36/Takeoff NOxEI_L~(1.159) Idle HCEI_L = 0.15 × Idle COEI_L - 2.0 In regard to application of the rich-dome technology to the (N+2) cycle based (N+3) mixers, the author tentatively gives it low probability of success barring success story stemming from Lee et al. [2012].