Day 1 (Thursday 31 July 2014)

The first talk of the first technical session was by J. Bosman form South Africa. He talked about a theoretical investigation of the NACA scoops for providing air to pneumatic turbulators. The turbulator is located on the trailing edge flap. The computational fluid dynamics model included the scoop, the plenum, and the wing section with blow holes. The results indicate approximately 2 – 5 N drag savings due to blowing, but also 1.9 N additional drag of the scoop.

Lukas Popelka of the Czech Republic reported of wind-tunnel tests, flight-tests, and theoretical modeling approaches. A particular focus was the experimental validation of an airfoil that was designed gradual flattening of the lift curve slope as stall is being approached. The purpose of this characteristics is to improve the thermaling behaviour in turbulent air. The experimental results reconfirmed the desired lift-curve effects, but also that the off-design conditions are good.

M. Weinzierl of the Akaflieg München introduced a concept study of a wing with a flexible leading edge. The drooped leading edge is supposed to improve the high-lift capabilities, thus enabling a smaller wing are. Preliminary results predict significant performance advantages over an ASW 27. To allow drooping the leading edge, the wing structure in front of the spar is hinged on the lower surface and has a highly flexible (in extension) element on the upper surface. The highly extensible element consists of a silicon-honeycomb sandwich design that allows significant extensions as demonstrated in experiments.

The next talk was presented again by Lukas Popelka who presented experimental results of measurements on airbrakes. The deployment of airbrakes drastically reduces the local angle of attack and lift coefficient. The larger the airbrake, the more effective. Other effects are the gap size and chordwise location (more effective if larger and more forward). The ensuing discussion was very animated and was about the operational issues of deploying airbrakes at high speeds. As pointed out by several members of the audience, one should deploy airbrakes well before reaching VNE.

The last talk was by G. Bramesfeld from Ryerson University in Toronto. He discussed a concept study of using a glider to explore the atmosphere of Titan (a moon of Saturn). The potential advantage of a glider is the simplicity of the system and possible durations and ranges that are much more significant than what is possible with drop probes.