TRANSITION CONTROL BY RIBLETS IN A SWEPT WING BOUNDARY-LAYER WITH AN EMBEDDED STREAMWISE VORTEX

A streamwise vortex was excited in swept-wing boundary layer by a vort ex generator placed close to the leading edge of a swept wing. It is s hown that in a three-dimensional boundary layer, riblets are able to r educe the magnitude of the vortex and suppress development of travelin g waves which reside in the vortex and lead to laminar-turbulent trans ition. The approach gives the experimental support for riblet applicat ion in transitional three-dimensional flows with streamwise vortices o f different nature. The situation can serve as a model of control of c rossflow-type vortices or vortices generated by a roughness.