Control of flow separation from a model wing at low Reynolds numbers

The results of an experimental investigation of the structure of the flow separated from the model of a straight wing with point sources of disturbances (bulges) made on its surface are presented. The variations in the three-dimensional flow pattern are analyzed as functions of the bulge shapes and positions. It is found that the flow can be controlled by means of mounting the bulges downstream of the separation line, in the return flow region, since in this case they hinder large-scale vortex formation in the separation zone. The results obtained show that there is an intimate connection between the vortices and the separation zone as a whole. Impeding the vortex structure formation can result in considerable variations in the separation zone structure, up to its complete disappearance.