Development of gortler vortices with "forced" wavelengths

Abstract

The development of boundary layer flows on a concave surface with 2.0 m radius of curvature in the presence of a??forceda?? wavelength G??rtler vortices was experimentally studied by installing a series of vertical wires of 0.2 mm diameter upstream of the surface leading edge. The details of the vortex flow structure which include the stages of evolution of the vortices, their interactions, the appearance of the secondary instability and the onset of the transition, were investigated. To experimentally confirm the appearance of the linear instability of the vortices with respect to spanwise perturbation, as indicated by the splitting and merging of the vortices, further experiments were also conducted at three different dimensionless wavelength parameters i?? of 88, 249, and 705, but at constant wire Reynolds number Red (where d is the diameter of the perturbation wire) of 40. The experimental results have successfully elucidated the development of G??rtler vortices.