Aerodynamics loads variations of wings with novel heating of top surface: Bioinspiration and experimental study

Applications of unmanned aerial vehicles are becoming more attainable through the increase in system efficiency. As seen in nature, birds like the albatross utilize the temperature effects resulting from their wings' color to increase their flight efficiency. In this paper, the effects that differences in surface temperatures of birds' black/white wings, colored flat plates, and airfoils with heating films is investigated. Such effects are applicable to the efficiency of fixed-wing drones. Experimentally, it is observed that the surface temperature of black birds' wings is over 50% higher than white wings under solar radiation. The application of a novel heated top surface on five airfoils results in the drag coefficient decreasing up to 60% and the lift coefficient increasing up to 70% for some airfoils in specified angles of attack compared to a non-heated top surface. This method of utilizing thermal effects can be considered as a new applicable way to increase the flight efficiency in fixed-wing unmanned aerial vehicles.