Design Considerations for Safe, All-Electric, Multirotor Propulsion Systems of eVTOL

Kurzfassung

As part of the arising worldwide efforts to provide new transportation possibilities within highly congested cities the German Aerospace Center (DLR) conducts extensive research in the area of urban air mobility within the project HorizonUAM. Aspects like vehicle design, infrastructure, UAM operation and public adaption are addressed in this context. This presentation aims to present the design considerations that need to be tackled for designing a safe, all-electric multirotor propulsion system for passenger transport UAM vehicles and shall present the recently derived first set of design guidelines. Thereby, the research encompasses the energy system, power management, motor-controllers, electric motors, transmission systems and rotors. In this context, several parameter studies were conducted and different propulsion system architectures were analyzed using a Model-based Systems Engineering approach. Their implications in terms of feasability based on state-of-the-art technology as well as safety and certification aspects are discussed within this presentation. The results indicate, that whether an eVTOL is safe and certifiable mainly depends on the number and the arrangement of the propulsors that provide lift and thrust for the multirotor vehicle. These design variables not only have an impact on the rotor radius, the disc-loading, the overall vehicle power and energy requirement and therefore the overall propulsion system weight but also on the design of the propulsion architecture, the requirement for redundant system components and possibly required reduction gears. Further research is required to optimize the propulsion architecture in terms of flight handling characteristics, system reliability and complexity, and vehicle weight.