Thickness effect of NACA foils on hydrodynamic global parameters, boundary layer states and stall establishment

The present study experimentally investigates the hydrodynamic behaviour of 2-D NACA (15%, 25% and 35%) symmetric hydrofoils at Reynolds number 0.5 x 10(6). Particular attention was paid to the hysteretic behaviour at the static stall angle, and a detailed cartography of the boundary layer structures (integral quantities and velocity profiles) is given to support the detachment mechanism and the onset of von Karman instability for thick hydrofoils. (C) 2010 Elsevier Ltd. All rights reserved.