Technical and Economic Viability of an EIS 2050 Geared Open Rotor

Abstract

The aviation sector is projected to grow rapidly over the next two decades and beyond. These projections coupled with ever more stringent environmental legislation call for action within the commercial aviation sector to radically reduce greenhouse gas emissions by 2050. It is perceived that by 2050 current state-of the-art direct-drive turbofans will have evolved into geared turbofans and geared open rotor engines for short haul missions. These changes in engine configuration may be attributed to calls from the Advisory Council for Aviation Research and innovation in Europe to dramatically reduce CO2 generation and greenhouse gas emissions by 2050. The geared open rotor architecture is predicted to significantly reduce fuel burn relative to a typical short-range year-2000 aircraft mission, and greatly reduce CO2 emissions per passenger kilometer. Although relative fuel-burn benefits have been estimated in various studies, the economic feasibility of developing the geared open rotor (GOR) engine configuration for potential manufacturers and operators has not been reported. Therefore, this paper describes methodologies employed to estimate the relative fuel burn benefit of a short-range year 2050 GOR engine-aircraft configuration. In addition, it details the financial feasibility of year-2050 short-range engine and aircraft concepts, for manufacturers and operators alike. An overview of the technical specifications of a potential ‘GOR2050’ engine configuration is provided. This paper further describes methods employed to predict the unit cost of a year-2050 engine and aircraft concept that might be offered by the manufacturers, as well as a revenue model for manufacturers in the 2050-timeframe. In order to capture the supplier–customer relationship between the OEMs and their customers, direct operating cost (DOC) and representative revenue models have been constructed for the operators. This paper also analyses the effects that potential future fuel price and taxation policies regarding emissions could have on the operational profitability of such an aircraft and engine combination. Based on a representative set of model inputs, an illustrative test-case for a year-2050 short-haul aircraft and engine combination predicts, with a 50% confidence level, that the minimum number of twin-engine aircraft sales needed to ensure the financial feasibility of the program would be 630 units. Furthermore, with a 50% confidence level, a potential operator could expect an internal rate of return over 7%. The impact of different fuel prices and taxation scenarios are quantified in terms of internal rate of return forecasts.