A great many studies have been directed towards understanding the flow over wings and, in particular, over a delta wing. Very surprisingly indeed, in our view, there exist no visualizations, from the laboratory, of the far-field development of the trailing vortex pair as it travels downstream, to our knowledge. Our flow visualization, involving novel free-flight gliding of a delta wing in water, shows for the first time, the exquisitely beautiful structure of the turbulent wake, in plan view. The fluorescence dye, illuminated by a laser, shows that the near wake comprises an interaction between the primary streamwise vortex pair with the "braid" wake vortices between the pair.

See also far wake of a delta wing and break-down of a vortex pair.

This work is supported by the Office of Naval Research.

Extract from the Gallery of Fluid Motion, Physics of Fluids, Vol. 7, No. 9, September 1995.