Feasibility Study for a Fuel Cell-Powered Unmanned Aerial Vehicle with a 75 kg Payload

Abstract

[EN] Among the possible electric powerplants currently driving low-payload UAVs (up to around 10 kgof payload), batteries offer certain clear benefits, but for medium-payload operation such as aerotaxisand heavy-cargo transportation UAVs, battery capacity requirements restrict their usage due to highweight and volume. In light of this situation, fuel cell (FC) systems (FCS) offer clear benefits over batteriesfor the medium-payload UAV segment (> 50 kg). Nevertheless, studies regarding the application of FCSpowerplants to this UAV segment are limited and the in-flight performance has not been clearly analysed.In order to address this knowledge gap, a feasibility analysis of these particular applications powered byFCS is performed in this study. A validated FC stack model (40 kW of maximum power) was integratedinto a balance of plant to conform an FCS. As a novelty, the management of the FCS was optimized tomaximize the FCS efficiency at different altitudes up to 12500 ft, so that the operation always impliesthe lowest H2consumption regardless of the altitude. In parallel, an UAV numerical model was developedbased on the AtLANte vehicle and characterized by calculating the aerodynamic coefficients throughCFD simulations. then, both models were integrated into a 0D-1D modelling platform together withan energy management strategy optimizer algorithm and a suitable propeller model. With the preliminaryresults obtained from the FCS and UAV models, it was possible to ascertain the range and endurance ofthe vehicle. As a result, it was concluded that the combination of both technologies could offer a rangeover 600 km and an endurance over 5 h. Finally, with the integrated UAV-FCS model, a flight profiledescribing a medium altitude, medium endurance mission was designed and used to analyse the viabilityof FC-powered UAV. the results showed how UAVs powered by FCS are viable for the considered aircraftsegment, providing competitive values of specific range and endurance.