|Item type||Location||Call number||url||Copy||Status||Date due|
|REPORT||Mesa Lab||101948 (Browse shelf)||http://mediatum2.ub.tum.de/download/823304/823304.pdf||1||Available|
Published in German
Techn. Univ., Diss., 2009--München.
Aircraft wake vortices have been observed to often live much longer than expected. Following aircraft encountering the wake vortices experience a rolling moment which depends on the deformation of the vortices. With the help of Large-Eddy Simulations (LES), this work investigates the dynamics of wake vortices in a turbulent and stratified atmosphere. Particularly, a method was developed which precisely determines the vortex core line. For the first time, the curvature of that line was analysed in sections. The results show that the frequency of vortex ring formation is astonishingly high. The descent speed of vortex rings is reduced and the cir- culation changes from flight direction to span wise direction. Before linking, mean curvature radii of the vortices reduce to the size of one initial vortex spacing. After linking, they may grow again. The expected rolling moment of following aircraft is estimated. In particular, the comparison with field measurement data obtained within the EU project AWIATOR confirms the presented results.