Flow structure over delta wings

High resolution Laser Doppler Anenionictcr (LDA) measurements using a novel technique have rewalcd considerable new detail of the separated vortcs flow OYCI a delta wing. It has been demonstrated that at modest local Reynolds numbers Based on chord (around Re,= 100,000 for an 8 5 O delta wing) the separating shear layer can form into strong, steady local sub-voniccs. These vonex s tmctu~es explain phenomena \rhicli have previously only been observed via flow visinliwtion. These highly ordered structures are of academic interest because of their unexpected nature, and niay have practical consequences if they recur in a parallcl form at higher Reynolds number in full scale separated flows.