The ULTIMATE project strives to develop powerplant concepts to Technological Readiness Level (TRL) 2 beyond the ultra-efficient powerplants expected to enter service in the year 2050. 

Improved thermal and propulsive efficiency

The best current aero engines only use 40% of the energy chemically stored in the fuel to do useful work. This energy conversion and its associated efficiency is comprised of two main factors:

  • the thermal efficiency (being around 50% in state-of-the-art engines), measuring how much chemical  energy is converted to kinetic energy
  • the propulsive efficiency (being around 80% in state-of-the-art engines), measuring how much kinetic energy is converted to thrust

Current research and development is in the process of radically increasing propulsive efficiencies through the introduction of advanced geared fan and open rotor concepts. Research and development on thermal efficiency is directed towards incremental improvement of existing solutions. Thermal efficiency is lost primarily through combustion irreversibility and heat wasted in hot core exhaust gases. These two loss sources dominate other sources such as turbomachinery inefficiencies and losses due to cooling. Consequently, it is indispensable to explore radical engine technologies to make very large advances on the thermal efficiency and to push the boundaries beyond the limits of what could be expected in year 2050 for propulsive efficiency.

Radical technology concepts at system and subsystem level

The engine technologies studied in ULTIMATE are highly innovative and adding extra steps to the simple gas turbine process of compression, burning under constant pressure, and expansion. Bringing these radical propulsion concepts into the market will constitute the greatest innovative step in aircraft engines since the introduction of the high bypass turbofan in the 1970s. Implementing new steps in the engine´s thermo-dynamical process to increase engine efficiency will require new or radically modified engine modules. These subsystems are not yet used in aviation. The ULTIMATE project will develop concept designs from scratch and redesign systems used in other engineering sectors to cope with the requirements of the new application. These activities generate great opportunities for innovation.

The design of subsystems and redesign to new requirements inherently generates a large innovation opportunity. At low TRL 1-2, the main focus is on functional design while the top-level-requirements are broken down to be applicable to functional modules. ULTIMATE will thus generate innovations on the system level, but also generate the subsystem requirements. The experience from previous research shows that it is primarily system function, aerodynamic configuration and temperature levels which provide input to design and innovation at the subsystem level. ULTIMATE activities will thus be concentrated to provide this important output.

Looking at the industry consortium participating in ULTIMATE, both engine system level and subsystem level suppliers are represented, providing a good connection to the market for engines and components. Further opportunities for the application of elements of ULTIMATE technologies will exist in other sectors where these industry partners are active.

Pre-competitive research for long-term economic impacts in Europe

The full implementation of ULTIMATE technologies into small, medium and large turbofan engines and its complete impact to the market for 50 – 800 passenger aircraft is a long term undertaking, even beyond the term of any new patents. Patent applications for radical aircraft engine technologies are increasing, but are not as common as those relating to more conventional aero engine systems. The full implementation of ULTIMATE engine technologies into small, medium and large commercial aircraft  is likely to be beyond the protection period afforded by patents filed today.

ULTIMATE’s long-term focus reduces the impact of any relevant blocking patents. On the other hand, some of the developed technologies may follow quicker paths into parts of the market, and thus patents will serve a purpose for these. With its long-term goals, ULTIMATE is concentrated on pre-competitive research, where results can be published. It is nevertheless expected that the involvement in ULTIMATE will be important for European engine industry to catch up and even get a head start in these technology fields.

The working process of the ULTIMATE project is set up to maximize innovation potential. Industrial partners are directly involved in technology screening as well as choosing how to mix and match the technologies on the long and short range evaluation platforms. Such targeted discussions between universities and industry involved in ULTIMATE create arenas where fresh ideas are created to stimulate innovation and to support reaching the ambitious goals of the Strategic Research and Innovation Agenda (SRIA) of the Advisory Council for Aviation Research and Innovation in Europe (ACARE). These discussions also support the objective that developed technologies, methods and results will be exploited efficiently by the industrial partners.