A PhD student working on fish skin to improve water processing in the laboratories of a well-known chemical firm in Geneva recently made an important step forward. His work explains how the surface structure of fish skin helps to optimize water stream, and reduce the drag, and help fish to go faster.

Using an improved version of finite elements method, together with wavelets modeling of the flow, he demonstrated that the small undulation of the skin’s surface artificially offsets the transition point. Thus, the profile produces less drag.

As initial calculations demonstrated that these results were not related to the water viscosity, the DuPont student decided to team up with a friend working in an aeronautics laboratory, and they reviewed everything together. As the results were applicable to airfoils, the lab management gave the go for building a prototype and to some wind tunnel testing.

The results are conform to theory: using an airliner-like wing profile, they obtained a reduction in drag of approximately 13%, with a penalty in lift of 2% only. Bargain ! Against what seemed logical, an undulation of the wing surface will massively help to increase airliners efficiency.

On the negative side, constructing such undulated wings is possible only with composite technology. A retrofit on metallic planes would cost way too much in terms of weight increase. Even modern manufacturing techniques won’t allow to build such profiles on metal.

Given the way how I got these information, I can’t publish any source, but as soon as more information will go public, I’ll keep you posted.