With the ECR, we aim to develop an insects-scale drone with unprecedented endurance inspired by the extraordinary flight ability of the dandelion seed
Our research is in fluid mechanics and it focuses on those conditions where the forces on a body immersed in a fluid are due to the formation of vortical flow structures. This often occurs in nature, where natural evolution has led to optimal solutions for complex problems. Hence, we seek inspiration from the fluid mechanics of plants and animals to develop new technology. Vortices, for instance, are exploited by natural flyers to fly stably and efficiently in the turbulent wind. Similarly, the forces on very thin surfaces, such as the wings of small drones and the sails of a yacht, are dominated by vortex flow. Our research aims to understand and, when possible control, the formation, stability and interaction of these vortices in order to improve performance, efficiency and survivability of different engineering systems.
The fluid mechanics principles that allow a passenger jet to lift off the ground are not applicable to the flight of small flyers. The reason for this is scaling: human flight requires very large Reynolds numbers, while small plants have comparatively small Reynolds numbers. At this small scale, there are a variety of modes of flight available to plants: from parachuting to gilding and autorotation.
Our group studies the aerodynamics of small plumed fruit that utilise a new mode of flight. If a dandelion fruit, for example, is picked up by the breeze, it can be carried over hundreds of miles. Incredibly, the filament structures of these seeds are mostly empty space, making this an extremely efficient mode of transport (https://doi.org/10.1038/s41586-018-0604-2). Moreover, the fruit can become more or less streamlined depending on the environmental conditions; in this way, they behave as a smart technology (http://dx.doi.org/10.1098/rsif.2018.0206). We are uncovering the novel engineering principles of these fruit, using a combination of numerical, analytical, and physical modelling. Our group has built a specialised wind tunnel, which we use alongside particle image velocimetry and high-speed imaging to visualise and measure the flow around these fruit.