TorPropel: Toroidal Propellers for Efficient and Sustainable Aviation

Why is there a need for this type of research?

The aviation industry is under increasing pressure to reduce noise pollution and improve fuel efficiency, particularly for propeller-driven aircraft. Traditional propeller designs have reached a point of limited optimisation, constraining further improvements in energy efficiency and acoustic performance. At the same time, the emergence of electrically driven platforms, including unmanned aerial vehicles (UAVs) and small-scale experimental passenger aircraft, has brought aircraft operations closer to urban environments. This proximity has intensified environmental concerns and prompted stricter regulatory requirements on noise and emissions. Without innovative approaches to propulsion, these emerging platforms may struggle to meet both operational and environmental standards. Additionally, the reliance on conventional materials and manufacturing techniques limits the sustainability, performance, and lifecycle efficiency of current propeller systems. The industry therefore requires new designs, materials, and production methods that can deliver significant improvements in thrust efficiency, noise reduction, weight reduction, and recyclability, while maintaining structural integrity and operational safety.

The TorPropel project addresses these challenges by developing toroidal (loop-shaped) propellers using advanced carbon composites and robotic manufacturing processes. The research scales propeller designs from centimetre-scale demonstrations to 1.7-metre diameter aerospace-grade components. Reprocessable, Repairable, and Recyclable (3R) vitrimer-based composites are employed to enhance sustainability, while Rapid Tow Shearing (RTS) enables precise, defect-free manufacturing. Integrated embedded sensor networks provide real-time structural health monitoring, enabling predictive maintenance and enhanced safety. Together, these innovations are expected to improve thrust efficiency by over 25%, reduce noise by more than 15 dB, cut propeller weight by 10%, and achieve 95% material recyclability.

What this research will change

TorPropel technology has the potential to transform propeller-driven aviation, from UAVs to electric vertical take-off and landing (eVTOL) aircraft and conventional propeller aircraft. The results will benefit aerospace manufacturers, urban air mobility operators, and regulators by providing quieter, more efficient, and sustainable propulsion solutions, while supporting compliance with environmental standards and reducing operational costs.

Role of the Brunel Composites Centre in this research

Brunel Composites Centre (BCC) contributes to the TorPropel project by leading the development and testing of advanced composite materials and structural components. BCC is responsible for evaluating material performance, optimising manufacturing processes, and integrating embedded sensors for structural health monitoring. Additionally, BCC provides expertise in simulation and testing to ensure that the scaled propellers meet aerodynamic, mechanical, and operational performance targets.

Project Partners

• University of Ioannina (Coordinator)
• Technical University of Munich
• Aristotle University of Thessaloniki
• Brunel University London (Brunel Composites Centre)
• iCOMAT Ltd 
• Evektor 
• CIDETEC 
• GMI Aero
• Limmat Scientific