"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates" "uuid:ae200352-5d8b-4551-900b-3d316cc5fd49","http://resolver.tudelft.nl/uuid:ae200352-5d8b-4551-900b-3d316cc5fd49","Experiments on a Flettner rotor at critical and supercritical Reynolds numbers","Bordogna, G. (TU Delft Ship Hydromechanics and Structures); Muggiasca, S. (Politecnico di Milano); Giappino, S. (Politecnico di Milano); Belloli, M. (Politecnico di Milano); Keuning, J.A. (TU Delft Ship Hydromechanics and Structures); Huijsmans, R.H.M. (TU Delft Ship Hydromechanics and Structures); van 't Veer, A.P. (TU Delft Marine and Transport Technology)","","2019","The Flettner rotor is attracting increasing attention as a viable technology for wind-assisted ship propulsion. Nonetheless, the influence of the Reynolds number on the aerodynamic performance of rotating cylinders is still unclear and under debate. The present study deals with a series of wind-tunnel experiments on a large-scale Flettner rotor in which the forces and pressures acting on the cylinder were measured for Reynolds numbers as large as Re=1.0⋅10 6 . The rotating cylinder used in the experimental campaign had a diameter of 1.0 m and span of 3.73 m. The results indicate that the lift coefficient is only affected by the Reynolds number in the critical flow region and below velocity ratio k=2.5. Conversely, in the velocity ratio range 1<k≤2.5, the drag coefficient is markedly influenced by the Reynolds number over the entire range of flow conditions analyzed. The power coefficient scales with the cube of the tangential velocity and it appears to be insensitive to the Reynolds number or whether the cylinder is spun in an air stream or in still air.","Magnus effect; Pressure measurements; Rotating cylinder; Rotor sail; Wind assisted ship propulsion; Wind tunnel tests","en","journal article","","","","","","","","","","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""