An insight into some innovative cycles for aircraft propulsion

Emissions are important drivers in the design and use of aero-engines. This paper presents a part of the work carried out in the VITAL (EnVIromnenTALly aero-engine) project; it consists of a parameter study on the application of three innovative thermodynamic cycles to aircraft propulsion, looking for benefits on fuel consumption, carbon dioxide, nitrogen oxides, and noise. These cycles are intercooler-regenerative, the wave rotor topping, and the constant volume combustor cycles. The work, starting from a next-generation ultra-high bypass ratio turbofan, the baseline, and considering two possible design conditions, presents the influence of the application of these new cycles or design changes to the baseline on emissions and on the required technological level, represented by the turbine entry temperature (TET). VITAL is a project supported by the Sixth Framework Programme of the European Communities. The results show that some significant benefits on emissions can be achieved although they are linked to significant technology improvements and in-depth studies of the new components involved in cycle implementation.