FROST

Air transport has grown by about 9% every year since 1950 and has made the world smaller on a human scale. However, commercial flights remain expensive and account for 2% of human emissions of CO2. As a result, airlines and the aviation industry envision tomorrow's transportation, which will require reduced costs, noise and greenhouse gas emissions. Aeronautics is a sector historically marked by a constant demand for innovation and technological progress. The search for reducing the environmental impact of air transport (emission of greenhouse gases and noise) is a natural part of this project. The evolution of thermal engine technologies, used for aeronautical propulsion (airplanes, helicopters, drones), arrives today at a limit which does not allow to glimpse of sufficient reduction of consumption and compatible pollutant emission of the fixed objectives with the new environmental standards (ACARE). To meet these expectations, electric power seems to be chosen for the development of future aircraft. Several manufacturers, governments and universities have started to work on hybrid or electric aircraft systems. At present, the electrically propelled architectures have been partially studied. Safeties, redundancy, the optimal use of hybrid architecture propulsion modules, or energy storage are just some of the steps that have yet to be taken. Each year, Airbus produces about 500 aircraft, ATR in pound about 50 and Eurocopter builds 300 helicopters. This represents a potential market of 1,500 high-power electric motors applied to hybrid or electric propulsion systems for aeronautics. For information, the average price of an Airbus A320 reactor (the CFM56-5B) is 7.6 million USD. "More electric" aircraft will reduce the overall cost of ownership, improve propulsive efficiency and reduce the impact on the environment. For example, developments for more electric aircraft are designed to replace the energy vectors that are hydraulic fluids and compressed air by the electric current in order to obtain a consequent significant reduction in fuel consumption. One of the most important parameters for aeronautical systems is the mass energy (Wh/kg) for storage systems and mass power (kW/kg) for electric actuators or power converters. The most electric aircraft currently is the Boeing 787. The total electric power installed is 1MW. This aircraft incorporates electric generators with a power density of 2.2 kW/kg. Projections for the next 20 years estimate that the power density could reach 9 kW/kg for conventional machines from 1 to 3 MW. To achieve higher objectives up to 20kW/ kg, disruptive technologies are studied. The use of materials such as superconductors could significantly increase the mass power of motors or generators. The main results obtained during the first RESUM project are: • Validation of electromagnetic design tools. • Realization of a superconducting machine at high speed, 5000 rpm, • Study of an original cryostat structure allowing a significant gain, about 30%, of mass torque. • Patent filings for ways to improve the proposed machine structure This new project that follows RESUM is devoted to the study and realization of a machine whose power is between 500 kW and 1 MW.