The ULTIMATE project develops synergetic breakthrough technologies in order to obtain step-change improvements in the propulsion and core thermal efficiency of modern gas turbine aero-engines. Following a down-selection approach, synergies between the technologies in the search for ultra-low carbon dioxide, nitrogen oxide and noise emissions will be explored in a structured way. The most promising combinations of radical technologies will then be developed for a short range European and a long range intercontinental advanced tube and wing aircraft (ATW), the two ULTIMATE year 2050 configurations.

The most challenging ACARE environment targets for 2050 are the 75% reduction in carbon dioxide (CO2) emissions per passenger kilometer and a 90% reduction in nitrogen oxide (NOx) emissions. Technologies currently at TRL 3-5, cannot achieve this aim. It is estimated that around a 30% CO2 reduction must come from radical innovations now being at lower TRL. Through the EU projects VITAL, NEWAC, DREAM, LEMCOTEC, E-BREAK and ENOVAL, the ULTIMATE partners have gained the most comprehensive experience in Europe on conception and evaluation of advanced aero engine architectures. Existing tools, knowledge and models will be used to perform joint optimization and evaluation against the SRIA targets to successfully mature the technologies to TRL 2.

The ULTIMATE project singles out the major loss sources in a state of the art turbofan. These are then used to categorize the following technologies which perfectly match the main fuel burn and emission objectives of the project and can be considered real breakthroughs. 

ULTIMATE technologies attacking the core exhaust loss and the bypass flow loss …
with the potential to further reduce fuel burn by 10% - 12% as compared to the ULTIMATE 2050 baseline configurations:

Piston topped composite cycle technology

  • ULTIMATE will mature the piston topping cycle technology to TRL 2
  • The combustion process in the conventional combustion chamber supplied with the pre-combusted working fluid will be assessed
  • The potential to reduce nitrogen oxide emissions will be estimated
  • The potential from more complete utilization of the oxygen in the core air flow will be explored

Nutating disc topped composite cycle technology

  • The conceptual design and optimization of a nutating disc based topping cycle concept targeting a commercial aero engine will be demonstrated
  • The potential to reduce nitrogen oxide emissions through reduced residence times will be estimated
  • Investigate the weight saving and operability potential of the nutating disc topping concept in relation to other constant volume technologies

Pulse detonation combustor technology

  • The potential to reduce nitrogen oxide emissions through reduced residence times will be estimated
  • Targeting the integration into an ULTIMATE powerplant configuration, an estimate will be provided for the efficiency of the downstream stator and rotor blade rows
  • An high pressure turbine will be designed to operate efficiently under the pulsating flow environment of a pulse detonation combustion chamber

ULTIMATE technologies attacking the combustor loss and the bypass flow loss … with the potential to further reduce fuel burn by 5% - 7% and the capability to reduce Nox emission, noise emission or core engine weight as compared to the ULTIMATE 2050 baseline configurations:

Intercooling technology

  • The performance benefits resulting from increased space availability for open rotor installations will be quantified and ultra-high pressure ratio installations will be developed
  • ULTIMATE will explore the capability to demonstrate a 15% reduction in NOx emission and a 10% reduced core engine weight over a year 2050 reference configuration 

Recuperation technology for intercooled engines

  • Novel installations inside the engine core, and the assessment of a wider range of tube geometries will be proposed
  • Concepts using different working fluids through a secondary fluid system will be assessed
  • The noise shielding capability of the heat exchanger will be explored by performing experimental measurements

Rankine cycle technology

  • The conceptual design and optimization of a secondary power cycle enhancing a commercial aero engine will be demonstrated
  • Various options such as a Supercritical Carbon Dioxide Cycle (S-CO2) or an Organic Rankine Cycle (ORC) will be explored
  • Radical condenser installations for low weight and failure scenarios of secondary fluid systems (Rankine cycle) to counter safety challenges will be assessed

Advanced propulsor and integration technologies

  • Targeting the optimisation of the ULTIMATE powerplant configuration, a variable pitch fan concept and a variable inlet guide vane concept will be developed for increased operability and variability
  • Radical concepts for variability in nacelle geometry will be assessed, using circumferentially retractable designs targeting open rotor concepts
  • A conceptual design for a Box-prop propeller concept will be assessed to radically reduce the noise generation from an open rotor configuration

A combination of ULTIMATE technologies for exploring synergies attacking the three loss sources…
with the potential to further reduce nitrogen oxide emission by 15% - 20%, fuel burn by 15% and noise emission by 10% as compared to the ULTIMATE 2050 configurations

Inter-turbine reheat technology

  • Optimised solutions for exploring synergies with intercooling, recuperation, Rankine bottoming will be provided
  • The availability of breakthrough very high temperature ceramic matrix composite materials for heat exchanger design will be assessed
  • ULTIMATE will explore the capability to demonstrate a 15% reduction in nitrogen oxide emission and a 10% reduced core engine weight over a year 2050 reference configuration 

Ambition on a powerplant and ULTIMATE configuration level

  • The combination of ULTIMATE technologies will provide – using the synergistic approach of simultaneously attacking the three large loss sources – a 15% reduction in specific fuel consumption, a greater than 18% reduction in fuel burn, a 20% nitrogen oxide reduction compared to the year 2050 reference configuration and a 3 dB reduction in noise per operation.
  • On TRL 2 level, ULTIMATE will demonstrate the capability of the down-selected and optimized ULTIMATE configurations to achieve the project objectives.