According to engineers, coating the rigid wings of airplanes with artificial bristles that mimic feathers could make them more efficient. An Italian team has demonstrated how feather-like structures help reduce drag on a cylinder and says they could have the same effect on underwater and aerial vehicles.
Although they may not look like they can have much of an effect, during gliding some covert feathers stick up at right angles to the wing’s surface and vibrate in the airflow. Bottaro and Julien Favier, also at Genoa, to test whether this affects flight performance, added synthetic coverts to a computer model of a 20-centimeter-diameter cylinder and put it in a virtual wind tunnel. (https://www.moreinspiration.com/article/4046/feather-coating-to-reduce-drag?t=physics)
A couple of students will explore the effect of the force of friction on flying and swimming objects. One of them is in the process of building a wind tunnel.