In this article, the results of research about stationary and secondary disturbances development behind the localized and two-dimensional roughness elements are presented. It is shown that the two-dimensional roughness element has a destabilizing effect on the disturbances induced by the three-dimensional roughness element lying upstream. In this case, the two-dimensional roughness element causes the appearance of stationary structures, and then secondary perturbations, whose frequency range lies lower than in the case of the stationary vortices excited by a three-dimensional roughness element.
BoikoAV, et al.Experimental study of the transition to turbulence at a single stationary disturbance in the boundary layer of an oblique aerofoil. J Appl Mech Tech Phys1995; 36: 67–77.
2.
ChernorayVG, et al.Secondary instability of a swept-wing boundary layer disturbed by controlled roughness elements. J Vis2010; 13: 251–256.
BoikoAV, et al.Generation of streamwise structures in a boundary layer of a swept wing and their secondary instability. Thermophys Aeromech2000; 7: 25–35.
5.
DeyhleHBippesH. Disturbance growth in an unstable three-dimensional boundary layer and its dependence on environmental conditions. J Fluid Mech1996; 316: 73.
6.
TolkachevSN, et al.Experimental techniques of the study of the vortex disturbances structure caused by point injection on the swept wing leading edge. Vestn NSU2012; 7: 66–79.
7.
BrylyakovAP, et al.Effect of free-stream turbulence on the flow structure near a wedge and the windward side of an airfoil. J Appl Mech Tech Phys2004; 45: 510–516.
8.
TolkachevSNGorevVNKozlovVV. Investigation of formation and development of stationary and secondary disturbances in the favourable pressure gradient area on the swept wing. Vestn NSU2013; 8: 55–69.
