Wake Interactions of a Small Uncrewed Aerial System with a Moving Vehicle

This study presents an experimental investigation of the aerodynamics relevant to the landing of a small Uncrewed Aerial System on a fast-moving ground vehicle. A Representative Ground Vehicle and small Uncrewed Aerial System have been constructed for experimental measurements of the wake interactions in a low-speed, recirculating wind tunnel. Quantitative flow image techniques are employed to probe how the sUAS interacts with the wake structures shed by the ground vehicle when the two are in close proximity. Tools are developed for quantitative comparisons of flow fields and turbulence spectra. Using this tool, it is possible to identify regions of the flow and relative positions of the two vehicles where wake interactions are mostly linear in nature. This near-linear wake interaction was observed to extend to the wake spectra in regions where the time-averaged flow fields were also near-linear. Finally, it is shown that these observations of a near-linear wake interaction do not hold when the sUAS interacts with highly decelerated regions of the ground vehicle wake.