A method for generating arbitrary wind patterns in fan array wind tunnel facilities

Fan array wind tunnels are a novel technology that promises to revolutionize testing of aerodynamic components by providing fine-grained control over the type of wind patterns that can be generated. However, general methods for producing desired wind patterns using fan array wind tunnels have yet to be elaborated. Here we present a gradient-based optimization algorithm for shaping the mean streamwise velocity distribution by modifying the fan rotational rates based on feedback of velocity information. The algorithm is tested experimentally on a fan array wind tunnel coupled with a grid of spatially distributed Pitot sensors which measure the velocity field. Results show that the proposed method can accurately produce user-specified wind shapes, opening new possibilities for the testing of low Reynolds number fliers in experimentally simulated atmospheric conditions.