EXPERIMENTAL STUDY OF AEROFOIL-WAKE INDUCED TRANSITION IN BOUNDARY LAYERS

摘要

Wake induced transition in multi-elementaerofoils and turbomachines are strikingresearch problems of interest because of theirinfluence on the aerodynamic performance. Toaddress this problem, experimentalinvestigations have previously been conductedto understand the interaction between a circularcylinder-wake and a flat plate boundary layer.However, the wake characteristics of thecircular cylinder and the aerofoil arecompletely different, resulting in distincttransition mechanisms on the downstream body.In this context, the present research addressesthe interaction problem considering a morerealistic system involving an aerofoil and a flatplate. Further, a comparative study betweenaerofoil-wake and circular cylinder-wakeinduced transitions has been performed. Inaddition, free stream turbulence (FST) inducedtransition is also considered for comparison.Parametric studies have been conducted tostudy the effect of factors such as the freestream Reynolds number and the distancebetween the aerofoil and the flat plate in bothstreamwise and wall normal directions.