Whale Tubercles
I have been interested in biomimetic design for many years, and one example I've found fascinating is aerodynamic improvements derived from the bumps on the leading edge of humpback whale pectoral fins (tubercles). These are presumed to create small vortices which delay flow separation (stall) and aid sharp turns during lunge feeding behavior. I had the opportunity to design a wind tunnel experiment for a class on fluid dynamics, so I decided to investigate this phenomenon.
I performed the test on a 3D printed Clark Y airfoil with interchangeable leading edges to test different configurations: a smooth leading edge, an edge with geometric similarity to a humpback whale fin, and an edge with bumps more closely spaced.
I found that while stall was delayed significantly, peak lift coefficient was slightly lower. Even without improvements to lift, delayed stall behavior could be valuable for improving aircraft performance.
“The lesson from such cases as the humpback whale is that a diversity of organisms needs to be maintained as a potential source of innovation as the application of biomimetic technology becomes ever more integrated into our lives.”