Visualization of boundary layer separation and passive flow control on airfoils and bodies in wind-tunnel and in-flight experiments
Institute of Thermomechanics, Academy of Sciences of
the Czech Republic, Dolejskova 5, Prague
8, Czech Republic
firstname.lastname@example.org ; email@example.com ; firstname.lastname@example.org ; Milan.Matejka@fs.cvut.cz ; email@example.com
2 Department of Applied Mathematics, CTU in Prague - Faculty of Transportation Sciences, Konviktska 20, Prague 1, Czech Republic
Infrared camera, Particle Image Velocimetry, smoke-wire, tuft filaments and oil-flow visualization techniques were used for wind-tunnel and in-flight investigation of boundary layer separation, both stall and separation bubbles, related to the low-Reynolds numbers transition mechanism. Airfoils of Wortmann FX66 series and FX66 series wing-fuselage interaction, as well as modern airfoils and their wing-fuselage geometry were subject to study. The presence of previously identified structures in the CFD modelling, such as horse-shoe vortices, was confirmed in the flow.
Wind-tunnels and in-flight measurements on sailplanes were carried out and effect of passive flow control devices - vortex generators - was surveyed; namely counter-rotating vortex generators and Zig-zag type turbulators were applied. Separation suppression and consequent drag coefficient reduction of test aircrafts was reached. PIV investigation was further extended by Time-Resolved techniques.
An important study on structure of the turbulent flow in the lower atmosphere, creating an environment of the soaring flight, was presented.
© Owned by the authors, published by EDP Sciences, 2012