Fan Array Wind Tunnels: Spatially Resolved Characterization and Data-Driven Modeling

Fan array wind tunnels are an emerging technology to design bespoke wind fields through the independent control of a grid of individually addressable fans. They are especially well suited for the turbulent, dynamic, spatially varying flight conditions found close to the ground, and they have been used successfully in recent applications from entomology to flight on Mars. However, the physics of fan arrays are still not fully characterized, making it challenging to design a custom wind field without heuristic trial and error optimization. We present the results of an experimental campaign of spatially resolved measurements of fan array wind tunnels under various non-uniform input profiles to begin addressing this modeling challenge. Specifically, we characterize the velocity field at various downstream locations and sensor configurations. We then test different data-driven modeling techniques on this input-output data, with the goal of enabling advanced model-based inverse design, optimization, and control.