Numerical Investigation of Wind Disturbance Around a Multirotor UAV in Crosswind and Vertical Flight

Uncrewed Aerial Vehicles (UAVs) are being increasingly utilized in a wide range of research applications, especially in meteorology. This is due to such factors as their ease of use, maneuverability compared to other forms of data collection, and for rotor- craft, the ability to hover. However, the rotorwash generated by UAVs can introduce significant disturbances, potentially affecting measurement accuracy from sensors. While several studies have investigated the rotorwash of individual UAVs utilizing Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD), there is limited exploration into how different rotor configurations and external wind conditions influence regions of turbulent flow around these craft. This study employs CFD to simulate various rotor configurations under various wind and flight conditions to study the regions of turbulence that form. One significant finding is that UAV operations with no crosswind and traveling in descending flight produce the most expansive turbulent regions. These results contribute to the broader understanding of UAV rotorwash effects and provide guidance for optimizing UAV designs for research and operational purposes.