Studies of Reynolds number effects on wing tip vortex positions by means of Laser Light Sheet (LLS) and Background Oriented Schlieren (BOS) technique under cryogenic conditions

Abstract

Wake vortex turbulence induced by large transport aircraft is problematic for airports’ capacity because of their hazardous impact on following aircraft. Safety rules defining minimum distances between landing and taking off aircraft are based on the strength and temporal duration of dissipation of the vortex turbulence. The wing tip vortex position is of major interest because interactions with vortices generated from e.g. the elevator of the airplane are desired to accelerate its decay. Experimental data are needed to enable quick and accurate vortex modelling. Up to now, these data are coming mostly from wind tunnels which cannot simulate the ‘real’ Reynolds and Mach number. It is usually assumed that this mismatch does not affect the results. The objective of this work was to provide the experimental tools to be able to investigate the question, whether the Reynolds number has a significant impact on the position of a wing tip vortex.