Flettner rotors are cylindrical devices used to enhance the aerodynamic performance of vehicles, particularly ships and aircraft. Named after their inventor, Anton Flettner, these rotors spin around their axes, creating a difference in air pressure on either side. This generates lift, which can improve stability and reduce drag. In maritime applications, Flettner rotors are often mounted on the masts of ships to harness wind energy, helping to propel the vessel and improve fuel efficiency. They can also be found in some modern aircraft designs, contributing to better maneuverability and performance during flight.