Sustainable Water-Injecting Turbofan Comprising Hybrid-electrics

Project Information

SWITCH

Grant agreement ID: 101102006

DOI

10.3030/101102006

EC signature date 9 December 2022

Start date 1 January 2023

End date 31 December 2026

Funded under

• Climate, Energy and Mobility

Total cost

€ 67 635 029,08

EU contribution

€ 48 501 871,65

Coordinated by

MTU AERO ENGINES AG
Germany

Periodic Reporting for period 3 - SWITCH (Sustainable Water-Injecting Turbofan Comprising Hybrid-electrics)

Reporting period: 2024-01-01 to 2024-12-31

Summary of the context and overall objectives of the project

The primary objectives of the SWITCH project are improving fuel burn and energy consumption by 20% and achieving a 50% reduction in the climate impact of both NOx emissions and contrails, compared to a state-of-the-art engine, hereby significantly reducing the three major warming effects of aviation on the climate — CO2, NOx, and contrails.

This 20% reduction in fuel burn meets the foreseen contribution from propulsion system side to the -30% goal on aircraft level as laid out in the Clean Aviation Strategic Research and Innovation Agenda (SRIA).
To achieve these objectives, the project develops the Dual-spool-hybridized heat recovering Second-Generation Geared Turbofan, which features a dual-spool hybrid-electric architecture, combining two Collins Aerospace megawatt-class electric motor generators within a Pratt & Whitney GTF™ engine, introduces Waste Heat Recovery to further improve thermal efficiency beyond the 2nd Gen GTF, and a low-emissions combustor to reduce NOx and nvPM emissions. The development of lightweight multifunctional structures and an optimized nacelle and thrust reverser support the integration of novel technologies into the powerplant.

Local air quality and noise levels around airports are improved through electric taxiing. The propulsion system will be compatible with 100% drop-in Sustainable Aviation Fuel (SAF) and its principle is suitable for powerplants that burn hydrogen. It addresses all climate-relevant market segments: short-, medium-, and long-range.

The SWITCH project is conducted by a global consortium, involving aircraft, engine and system OEMs, key tier I suppliers and leading research institutes in combustion and propulsion. This unprecedented collaborative effort will leverage synergies between European and national programs, ensuring that the project is well-placed within the context of the Clean Aviation initiative.

IBy program conclusion, SWITCH matures the dual-spool hybridized turbofan to Technology Readiness Level (TRL) 5 through ground demonstration of the full propulsion system, and the waste heat recovery concept to TRL 4 through validation of its key enabling technologies. In Phase 2 of Clean Aviation, the dual-spool hybrid-electric configuration is flight tested and matured to TRL 6, and Waste Heat Recovery System demonstrated to achieve TRL 5.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the reporting period, the core of the work performed in SWITCH covered:

Hybrid-Electric Propulsion & WET Concept Elaboration:
The Water Enhanced Turbofan (WET) Concept Review was concluded in March and follow-up activities from this Review took until Q3.
The Concept Review revealed important challenges that lead the consortium to propose a re-orientation of the SWITCH project. The core principle of the WET concept, recovery of waste heat of the engine, will be further matured in the WHR (waste heat recovery) concept.
In Q4, WHR Concept optimization studies were launched, and the Biennial Model Based Performance Estimate was provided to CAJU Impact Monitoring. Additionally, the Methodology for SMR Engine Assessment was completed, marking another key achievement for the year.
The Hybrid-Electric Propulsion (EAP) concept work package achieved a major milestone with the completion of its Preliminary Design Review (PDR) in June, followed by the issuance of the EAP engine Preliminary Design Report in July.

Hybrid-Electric Engine Demonstrator:
For the electrical powertrain, several component Preliminary Design Reviews (PDRs) were completed, and critical actions for the EAP system PDR were closed. Progress continued on interfaces and requirements, aid definition and concretization of test objectives for the upcoming powertrain Labtest (GRID test).

WET Technology Maturation:
Throughout the year, the WET Technology Maturation project achieved several significant milestones across various components. With the transition from WET to WHR, most key technologies are retained since they continue to be relevant for the waste-heat recovery concept, or since their singular contributions are positively impacting the project KPIs.
The condenser rig was commissioned in Q1, and testing began. Although activities were put on hold in Q3 for further restructuring, work performed on the Matrix Design & Optimization Tool was concluded and delivered in Q4.
The first test campaign for the combustor was launched at DLR in Q1 and continued successfully into Q3 with steam injection, marking a key achievement for the year.
The vaporizer cold demonstrator concept review was completed in Q1, and the vaporizer design report was issued, with activities progressing according to plan throughout the year.
The water recovery test campaign began in Q1 and continued steadily, showing consistent progress.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

SWITCH’s overall objective is to demonstrate at TRL4/5 the disruptive ultra-efficient next generation SMR propulsion concept, the Dual-spool-hybridized heat recovering Second-Gen Geared Turbofan, resulting in 20% lower fuel burn and more than 50% reduction of non-CO2 related climate impact compared to a 2020 market available state of the art aero engine. The concept will be compatible with SR/SMR aircraft architectures and is even scalable to all other relevant thrust classes

By 2026, SWITCH matures dual-spool hybridization technology to Technology Readiness Level (TRL) 5 through ground demonstration of the full propulsion system, and the waste heat recovery concept to TRL 4 through validation of its key enabling technologies. The demonstration plan will be detailed to reach TRL4 for the WHR concept at project completion.
The dual-spool hybridization will be matured to TRL4 through the development and testing of its sub-systems components in the laboratory environment and to TRL5 in 2025 through integration and testing of the full system in an engine ground demonstrator. The engine ground demonstrator will be designed and fabricated to be flight worthy to enable flight testing early in Phase 2. A roadmap towards full-scale demonstration of the propulsion system compatible with TRL6 at aircraft level before the end of the Clean Aviation programme and compatible with an EIS by 2035 will be delivered.
In Phase 2 of Clean Aviation, the dual-spool hybridization configuration will be flight tested and matured to TRL 6 by 2030 and Waste Heat Recovery System demonstrated to achieve TRL 5 by 2030.

Aspirational Aircraft Concept with dual-spool-hybridized heat recovering Second-Gen Geared Turbofan