Design and Characterization of a Modular Wind Wall for VTOL and Fixed Wing UAV Testing

Outdoor flight testing for VTOL and fixed-wing UAVs is often unpredictable due to weather and wind conditions. However, a low-speed wind tunnel offers more control but incurs higher costs for larger test areas. By developing a modular wind wall, repeatable and controlled wind profiles can be produced. The wind wall consists of modular wind-generating units that can be stacked vertically and horizontally. By generating variable wind conditions that closely resemble real-world flight environments, UAV flight tests can be accurately simulated, providing valuable insights into their aerodynamic performance and flight stability. To evaluate the flow of the wind wall, several design parameters are analyzed within a single duct test module. These parameters include honeycomb meshes with varying cell widths, different distances between the motor and meshes, propeller configurations, and duct geometry. By measuring numerous duct configurations, turbulence intensity and flow uniformity are assessed. This testing aims to maintain turbulence intensity below 5%. A digital seven-hole probe system, mounted on an X/Y linear traverse, is used to measure the velocity and flow angularity at the exit of the duct. By accurately reproducing real-world flight environments in a laboratory setting, the wind wall will provide a valuable platform for evaluating UAV performance and stability.