Propulsion system for next generation rotorcrafts

The outcome should contribute to:

• Versatile European propulsion system to fulfil the increasing systems power demand.
• Affordable propulsive system such as cost competitive for the whole life cycle.
• Robust and reliable system with good maintainability, even when operating in harsh environments.
• Easy to maintain and repair such as supported by predictive maintenance tools (digital twin) and 3D intuitive documentation and instructions for maintenance crews.
• Sovereign European propulsive solution for new rotorcraft applications.
• Reinforce the EU sovereignty and independence on these strategic platforms through the strengthening of the EU supply chain and integration of EU Member States’ and EDF Associated Countries’ system capabilities and provide a product free from export control restrictions by non-EU or non-EDF Associated countries.

The objective of this call is to develop and mature the technologies required for a new state-of-the-art, breakthrough, affordable, efficient, and high-power (above 3000 shp / 2.237 kW) engine for future generation of EU military rotorcraft systems.

Specific objective

The objective of this research topic is to better understand and analyse the future needs EU Members States and EDF Associated Countries and the transition to future rotorcraft features, concepts, and capabilities, and to derive specific design parameters for next generation propulsion systems. Conception and pre-design of an alternative propulsion system for rotorcraft platforms must be performed.

There are currently no civil applications for a turboshaft engine in the considered EU Next Generation Rotorcraft (ENGR) power range. Hence, there is a need to develop new relevant technological bricks for a European high-power engine.

Indeed, the development of a new engine may be longer than for a new rotorcraft. It is therefore needed to work on both topics simultaneously and in a consistent manner so that effects of the engine are considered in the rotorcraft architecture and vice versa.

The proposals must address:

• A new propulsion system for rotorcraft platforms with a breakthrough engine that closes the technological gap in the power-range above 3.000 shp / 2.237 kW.
• A significant increase of efficiency and performance indicators compared to the actual state of the art propulsion systems for rotorcraft platforms.
• Ensure that the propulsion system for rotorcraft platforms’ architecture and power requirements match the requirements of the ENGR.
• Improve propulsion system for rotorcraft platforms’ capabilities to meet military requirements for the future operations and particularly for multi-mission military rotorcraft (such as armed reconnaissance, strike, combat, and ordinary search-and-rescue (SAR), MEDical EVACuation (MEDEVAC), CASualty EVACuation (CASEVAC), utility, air assault and close aerial support) and flexible mission requirements, such as low emission signature, high operational availability, reliability and maintainability.
• Minimise deterioration caused by harsh environments (e.g., sand, dust, maritime, ice, snow, water, wide range of temperatures, etc.)
• Reduce fuel usage and ensure high power-to-weight ratio by a highly efficient thermodynamic cycle, for example, by ensuring a high-pressure ratio compressor, a high-temperature combustor and turbine, low-emission combustor, and highly efficient and light weight power turbine. To achieve this goal, an advanced fuel system as well as an advanced control and monitoring system must also be studied.
• Reduce costs through design concepts for minimum life cycle costs.
• Use green technologies aiming at significantly lowering CO₂ emissions on the entire lifecycle and notably improving sustainability and recyclability.
• Reduce the risk for the future full propulsion system for rotorcraft platforms development program as much as possible, thanks to early research and pre-development and maturation of key technological bricks.
• In addition, the propulsion system for rotorcraft platforms must be ready for the use of conventional fuels, Sustainable Aviation Fuels (SAF) and provide robustness for the usage of combustible fuels of lower qualities (e.g., higher sulphur content, impurities) in different regions of the world with anomalous specifications, e.g., Jet A, JP, SAF, Avgas, Mogas.
• Maximise operational usability by increasing times between inspections and overhaul.

However, proposals should not address research activities on rotors, gearboxes and shafts and should be limited to the engine itself and its components (for example the fuel system as well as the engine control and monitoring system).

Types of activities

The following types of activities are eligible for this topic:

Accordingly, the proposals must cover at least the following tasks as part of mandatory activities:

• Generating knowledge:
  • Identification of hybridisation concepts that brings benefit to a rotorcraft (for example: micro-hybridisation, series hybridisation, parallel hybridisation, etc.)
  • Identify new generation of materials for rotorcraft engines applications.
  • Study on artificial intelligence (AI) for engine control and monitoring.
• Integrating knowledge:
  • Preparation of technological and integration solutions for next generation propulsion system for rotorcraft platforms for military applications. These should be produced, developed, and manufactured with the objective of ensuring EU sovereignty and providing optimal performance and reliability for the targeted wide-range applications.
  • Possibilities to integrate technological developments developed through other civil or military projects for a propulsion system with a reduced environmental footprint, through hybridisation solutions and operation with new Sustainable Aviation Fuels (SAF), but also allowing more autonomous operation.
• Studies:
  • Maturation of technologies to achieve specific performance (aerodynamic, thermal, regulation system, potential hybridisation, or electrification of propulsion, etc.) at an affordable cost and easy to maintain.
  • Scalability and dissemination of the results into other products and in various types of aircraft and/or platforms.
  • Study of an engine design adapted to a variable-speed rotor helicopter.
  • Study on improved engine & fleet management and on concepts for adapting civil engine fleet management systems on military applications for improved availability and reduced life cycle costs (LCC).
  • Cost-benefit analysis and forecast of effects on maintenance-effort for each technology.
  • wide usage of 3-D-printed components and novel manufacturing processes associated with innovative repair solutions.
• Design:
  • Design of a propulsion system for rotorcraft platforms that fulfils the requirements mentioned herein.
  • Possibility to perform real-time engine monitoring, trouble shooting and predictive performance and maintenance in deployed operations with remote assistance through virtual reality, augmented reality tools by using a digital twin and AI-based prediction tools. Troubleshooting, predictive performance and maintenance should also be operative offline for some specific operations when external communication is not allowed or not possible.
  • Design an engine with very simple and lean maintenance: Highly connected engine with data-driven services for highly predictive maintenance and condition-based maintenance.
  • Extended life for engine components and equipment.
  • Standardisation and significant reduction of parts, devices, and modules.
• • Any other solution that must contribute to optimise lifecycle costs, such as advanced fuel, control, and monitoring systems, that includes new fuel pump technology to provide increased fuel flow, higher accuracy of the fuel metering system to deliver the required performance (unprecedented power density, responsiveness…) and new control laws to deal with a hybrid-electric propulsion system.

In addition, the proposals may also cover the following tasks:

• • Study of the technologies developed in the frame of this call, as they may also benefit other propulsion solutions and different rotorcraft applications.

The proposals must substantiate synergies and complementarity with foreseen, ongoing, or completed activities in the field of military rotorcrafts, notably those described in the call topic EDF-2021-AIR-R-NGRT related to Next Generation Rotorcraft Technologies and EDF-2024-DA-AIR-NGRT related to Next Generation Rotorcraft, to ensure that the engine and the rotorcraft architectures remain consistent.

Functional requirements

The proposed product and technologies should meet the following functional requirements:

• Scalable technologies to cover a power-range above 3.000 shp / 2.237 kW.
• Specific Fuel Consumption (SFC) reduction by 25 to 35 %, compared to in-service engines of the same power class.
• Horsepower to weight ratio best in class at the time of its entry into service.
• Lower production and operational costs compared to what the future competition could offer thanks to new manufacturing processes and means, innovative maintenance concepts and high level reliability/ availability of the engine components.
• Substantially reduced aircraft fuel burn and hence CO₂ emission, compared to the actual standard.
• Compatible with current and future Sustainable Aviation Fuels.
• Very high level of availability in all military operating conditions.
• Capacity to operate in harsh environments (e.g., sand, dust, maritime, ice, snow, water, wide range of temperatures, etc.) without significantly degrading the engine performances and availability.
• Improve the engine robustness to make the engine safer, more reliable, and simpler to operate.
• Reduced detectability and increased survivability (i.e., very low infrared (IR) and noise signature).
• Higher electrical power capacity for future on board systems and hybridisation requirements.
• With regards to the propulsion system (twin-engine system), it must allow the crew to cruise on a "single engine mode" as a normal operating mode of the helicopter.