Modelling gust-encounters on UAVs with cyber-physical fluid dynamics

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Micro-aerial vehicles (MAVs) are futuristic remote sensing platforms, ranging in size between that of large insect to a small bird. They are being developed to investigate subjects that would be difficult or impossible to access with a larger platform, or where the vehicle must be inconspicuous. For instance, an MAV developed for search and rescue may be able to navigate cramped or wooded areas, while an MAV meant for wildlife monitoring may be able to operate near birds without startling them. Moreover, the small size and low cost of MAVs allow for greater access to traditional remote-sensing tasks, such as environmental and infrastructure monitoring. However, current MAV designs cannot operate in the open air as they are very vulnerable to gusts. Inspiration from natural flyers such as birds and insects, which are adept at managing changing winds, has therefore become a common theme in MAV development. Small biological flyers do not stay aloft using the same strategies as common commercial aircraft. Instead, they use their wings to both propel themselves forward and to stay aloft; flapping-wing flight must be described with an entirely different set of engineering tools that account for the complex, time-varying motion of flapping wings. ***The proposed research will develop such engineering tools with a specific focus on understanding gusting loads. These tools will be developed after first determining the flow physics of gust encounters. This physical investigation will be carried out experimentally in a water channel, where a gust generator will be used to expose a flapping wing to unsteady flows. Gust loadings will be measured with a load cell in the wing, while the flow around the wing will be observed with dye-flow visualizations and Particle-Image Velocimetry. After determining the physics of the gust encounters, and after feeding this physics into an engineering model, we will be able to improve experimental facilities for the purposes of studying gusts and to develop new methods to limit the variations in lift and drag experienced by a wing exposed to gusts. This research program will also train new engineers to be experts in both flow physics and the mechanics of flight.