An Innovative Treadmill-Magnus Wind Propulsion System for Naval Ships
Ahmad Sedaghat, Mohammad Ali Badri, Mohsen Saghafian and Iman Samani
The Magnus force was successfully employed by Flettner in his ship Buckau operating with two large propelling cylinders. The spinning cylinders produced propulsive force from the wind on seas as a clean and free source of energy. The rise of fossil fuel costs, extinction of fossil fuel resources, and environmental issues such as global warming and pollutions produced by fossil fuels have caused a renew interest in Flettner type propulsion in naval ships. This is becoming a hot topic in Europe and the rest of world. Many other applications of producing high lift values from spinning symmetrical cylinders have failed due to high values of drag force and also rapid increase of frictional torques. In this paper, the new application of Treadmill-Magnus, wind driven propulsion system is introduced which can be effectively used for any size ships. To show validity of the concept, the NACA0020 aerofoil section with treadmill skin is computationally investigated at the low Reynolds number of 8.2104. The viscous fluid flow solutions were obtained at variety of treadmill speeds of the aerofoil skin and different incident angles. The results show that high lift to drag ratios may be obtained using treadmill motion.
Magnus effect, propulsion, treadmill motion, NACA0020 aerofoil, CFD
Assistant Professor, Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.