Atmospheric flow simulation strategies to assess turbulent wind conditions for safe drone operations in urban environments

As the technology of small aircraft systems continues to improve and the number of their possible applications grows, they are likely to be used more frequently in urban environments soon. Such environments are especially dangerous due to their high population and structural density in combination with challenging atmospheric conditions. Particularly the local wind field with its often unknown wind shear and turbulence characteristics endangers manned and unmanned aerial vehicles. Therefore, knowledge of the local turbulent wind is essential to ensure safety for the aircraft and the people onboard as well as on ground and should thus be incorporated in mission planning. This study presents a framework of how atmospheric flow analyses can contribute to safe drone operations in urban environments. High-resolution simulations are carried out, utilizing the large-eddy simulation model PALM, which can resolve turbulent flow and building structures down to the meter scale. Our results highlight the advantages and the necessity of using turbulence-resolving models to reasonably arrange a future drone operation network within cities. Because large-eddy simulations of urban environments are still computationally expensive, a meteorological data base for each urban setup should be established to obtain the relevant wind information for mission planning.