Integration and Digital Demonstration of Low-emission Aircraft Technologies and Airport Operations

Project Information

INDIGO

Grant agreement ID: 101096055

DOI

10.3030/101096055

EC signature date 5 December 2022

Start date 1 February 2023

End date 30 September 2026

Funded under

• Climate, Energy and Mobility

Total cost

€ 3 111 446,25

EU contribution

€ 3 111 446,25

Coordinated by

BARCELONA SUPERCOMPUTING CENTER CENTRO NACIONAL DE SUPERCOMPUTACION
Spain

Periodic Reporting for period 1 - INDIGO (Integration and Digital Demonstration of Low-emission Aircraft Technologies and Airport Operations)

Reporting period: 2023-02-01 to 2024-07-31

Summary of the context and overall objectives of the project

The INDIGO project (Integration and Digital Demonstration of Low-emission Aircraft Technologies and Airport Operations) addresses the urgent need to reduce aviation’s environmental footprint. With rising air traffic, the industry faces increasing scrutiny over its contributions to climate change, local air quality degradation, and noise pollution, particularly around airports. In response, INDIGO aims to design and validate innovative aircraft technologies that drastically reduce emissions and noise while maintaining operational efficiency.
At the core of the project are Distributed Hybrid Electric Propulsion (DHEP) systems and Large Aspect Ratio Wings (LARW), integrated into a new medium-range aircraft concept. These technologies offer breakthroughs in reducing CO2, NOx, particulate matter, and noise during critical flight phases near airports, improving local air quality and reducing environmental impacts on communities.
The project focuses on advancing low Technology Readiness Level (TRL) technologies and integrating them into the broader ecosystem of air traffic management and airport operations. It employs multidisciplinary approaches, including advanced digital modeling, to optimize operational procedures like taxiing, take-off, and landing for future aircraft, with the goal of reducing emissions by up to 50% by 2050.
Social sciences and humanities play a key role in the project, addressing the societal impacts of these innovations. Improved local air quality and reduced noise levels will benefit public health and quality of life. INDIGO also aligns with the European Green Deal objectives, contributing to the EU’s climate-neutral mobility strategy and enhancing the competitiveness of European aviation while addressing global environmental goals.
Expected to set a new benchmark for sustainable aviation, INDIGO offers significant benefits to both industry stakeholders and local communities.

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

During the first reporting period (M00-M18), the INDIGO project advanced its technical and scientific goals, focusing on sustainable aircraft technologies to reduce emissions and noise, particularly through hybrid propulsion and advanced design.
Key Achievements:
1. Baseline Aircraft Concept (DHEP-LARW): The project designed a baseline DHEP-LARW aircraft (Distributed Hybrid Electric Propulsion and Large Aspect Ratio Wings), aimed at reducing emissions and noise around airports while maintaining cruise performance. Multidisciplinary Design Optimization (MDO) was used to optimize the aircraft's wing and propulsion systems, improving fuel consumption and environmental impact.
2. Hybrid Propulsion System: The project developed a hybrid propulsion system that allows flexible power distribution between electric motors and gas turbines. This system optimizes power usage during flight phases, including cruise, climb, and Landing and Take-Off (LTO), reducing emissions and noise, particularly near airports.
3. Performance and Noise Models: Performance models, including noise assessments of the distributed hybrid electric propulsion system, were developed. These models predict noise and emissions reductions, especially during take-off and landing, aiding in evaluating the aircraft's environmental footprint.
4. Optimization of Flight Operations: Flight operations, including take-off, landing, and taxiing, were optimized to reduce fuel consumption and emissions. Power distribution between electric and conventional propulsion during the LTO cycle was fine-tuned to reduce noise and emissions.
5. Environmental Impact Assessment: A comprehensive environmental model was developed to evaluate local air quality and noise. It assesses the aircraft’s impact on NOx, SOx, and particulate matter, ensuring alignment with EU environmental targets.
Summary:
The work completed provides a strong foundation for the development of low-emission aircraft with distributed hybrid propulsion, optimizing flight operations and air traffic strategies. These advancements position INDIGO to significantly reduce emissions, fuel consumption, and noise, contributing to more sustainable aviation.

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)

During the first reporting period, the INDIGO project achieved significant advancements, pushing the boundaries of current aviation technologies in aircraft design, propulsion systems, and environmental performance.
Key Results Beyond the State of the Art:
1. Distributed Hybrid Electric Propulsion (DHEP): INDIGO advanced DHEP technology, integrating electric systems with gas turbines. This hybrid configuration optimizes power distribution during cruise, take-off, and landing, improving emissions and noise, particularly during the Landing and Take-Off (LTO) cycle. The aircraft uniquely combines distributed propulsion and large aspect ratio wings.
2. Multidisciplinary Design Optimization (MDO): INDIGO's MDO framework integrates aerodynamics, propulsion, structures, and noise into one platform, optimizing design by balancing fuel efficiency, emissions, and noise. This sets a new standard for minimizing environmental impact while enhancing performance.
3. Noise Reduction Techniques: New noise reduction techniques using distributed propulsion and optimized propeller configurations control noise, especially during take-off and landing. The combination of large aspect ratio wings and hybrid propulsion further reduces noise, meeting future standards.
4. Environmental Impact and Local Air Quality: INDIGO developed a high-fidelity environmental model to assess local air quality and noise (LAQN) near airports. Using high- and low-fidelity simulations, the model predicts reductions in NOx, SOx, PM, and VOCs. The multivariate optimization provides a more comprehensive environmental assessment.
5. Hybrid Power Optimization for LTO: INDIGO’s hybrid power system enables precise control of electric and conventional propulsion during the LTO cycle, minimizing fuel consumption and emissions, optimizing energy management to reduce the aircraft's environmental footprint.
Overall Significance:
The INDIGO project delivers innovations in hybrid-electric propulsion, noise reduction, and environmental performance. By combining distributed propulsion with MDO, the project ensures compliance with EU Green Deal and ICAO standards, paving the way for next-generation sustainable aviation.

3D view of the INDIGO baseline