Vortex interaction on a LEX configuration

Flow visualization experiments were conducted in a water channel and a low-speed wind tunnel at Reynolds number of 1.54 x 10(4) to 1.2 x 10(5) for a leading-edge extension model, which is referred to as a NASA TP-1803 model in this study. In addition, particle image velocimetry velocity measurements were taken in the water channel to obtain the quantitative information about the three-dimensional velocity field over the strake and wing surfaces. The results obtained at low, medium and high angles of attacks represent three distinct cases of interaction between the strake and wing vortices. Namely, at alpha = 5 degrees and 10 degrees the strake and wing vortices were developed over the wing surface without significant interaction noticed; at alpha = 20 degrees, the strake vortex strongly interacted with the wing vortex in an intertwining manner, which was sensitive to Reynolds number; at alpha = 30 degrees, the breakdown of the strake vortex took place close to the junction of the strake and the wing; thus, the interaction of the strake and the wing vortices appeared to be less significant than the case of alpha = 20 degrees.

Automated summary

The flow visualization experiments conducted on the NASA TP-1803 model at different angles of attack revealed varying degrees of interaction between the strake and wing vortices, with particularly strong interaction observed at 20 degrees and vortex breakdown at 30 degrees.