Caleb Jordan-McDaniels, Claire Fogarty, Niharika Misal, Mackenzie Werner, Simi Kapila, Justin Langs
What is the problem your team addressed for this challenge and how is it related to climate change?
Electricity production is one of the largest contributors of greenhouse gasses worldwide. Many techniques for generating clean electricity have been devised including ocean-based systems such as tidal kites which, due to their ability to generate electricity from low-velocity currents, have the potential to revolutionize ocean-based energy generation. There are, however, several issues, particularly when it comes to reliable control systems, that must be addressed before these kites are ready for wide-scale deployment. For that reason, we looked to nature in order to design a passive control system for tidal kites that maintains high levels of stability.
What does your design solution do? How does it solve or improve the problem you selected?
Our passive control system maintains kite stability while allowing the kite to achieve high-speed spirals when flown across a current. The spiral motion is created due to a small level of asymmetry between the wings of the kite which causes one side to produce less lift than the other. Stable flight is attained through several mechanisms including swept wings which allow for pitching stability, washout in order to prevent stalling and undesired spinning, and, perhaps most importantly, dihedral wing angle which brings considerable spiral stability.
How was your solution inspired by nature? What organisms did you learn from and how did what you learned inform your design?
This design is based very closely on the seeds of Alsomitra macrocarpa, a species of vine that grows high in the trees of Indonesian rainforests. Due to the advantages of spreading offspring far from the parent plant, Alsomitra seeds have evolved to utilize all of the characteristics discussed above—swept wings, washout, and dihedral wing angle—which makes them extremely well suited to long-distance gliding.