Geared open rotor performance assessment for short range civil aviation

Abstract

As a consequence of increased stringent environmental regulations in a highly competitive market, airlines require radically more efficient and environmentally friendly aircraft.
Engine manufacturers propose four different alternatives for the replacement of the A320: the geared turbofan, the advanced turbofan, the counter-rotating geared open rotor and the counterrotating direct drive open rotor. The open rotor technology offers the more potential fuel saves than the other options but there are major challenges associated with the development of this technology such as: the design of reliable counter-rotating components, the design of silent propellers, the design of a pitch changing mechanism capable of safely operating in hot sections of the engine and the stable operation in reverse thrust setting.

In order to design the most efficient engine that meets the certification requirements, a multidisciplinary simulation tool is required to quantify the implication of different design and operation choices. This article focuses on the performance module of this simulation tool and on the performance assessment of the geared open rotor architecture. The simulation results suggest that the geared open rotor has the potential to reduce the fuel consumption by approximately 21% compared to a current turbofan. This is directly translated into a 21% reduction of gaseous emissions and approximately a 7.7% reduction of the average European airline total operating cost.