Thermodynamic Analysis of an Aircraft Engine to estimate performance and emissions at LTO cycle

Abstract

Nowadays, pollutant gases emitted from the civil aircraft are doing more and more harm to the environment with the rapid development of the global commercial aviation transport. Emissions of aircraft engines whose rated output is greater than 26.7 kN and whose date of manufacture is after 1 January 1986, are regulated under the provisions established by ICAO to guarantee that engines, at the reference emissions Landing and Take-Off cycle, do not exceed certain regulatory environmental limits. For this purpose, an analysis of the aircraft engine at Landing and Take-Off cycle conditions to determine the emission is important.The aim of this paper is to study the GE90-94B engine built on the proven success of the early GE90 engine models, that with a nominal thrust of 416.8 kN and a dual dome annular combustor, powers the Boeing 777-200 aircraft. The engine is modelled and simulated with the modular code ESMS, that has the ability to simulate a generic engine at design and off-design conditions without creating a new source program. A thermodynamic design simulation at cruise condition has been realized, using a few known operating characteristics and some general design parameters can be determined. Thereafter an off-design analysis varying the operating mode has been reported; consequently, the thermodynamic parameters as fuel consumption, thrust, bypass ratio, turbine inlet temperature and exhaust temperature change. Moreover, using the results of the ESMS simulations it is possible to estimate, with a correlation, the NOx emissions during the Landing and Take-Off cycle.