POSSIBLE TYPES OF FLOW ON LEE-SURFACE OF DELTA WINGS AT SUPERSONIC SPEEDS.

Experiments were conducted to study the types of flow that occur on the lee surface of delta wings at supersonic speeds. Two sets of flat topped delta wings of different thickness (wedges with 10 degree and 25 degree normal angle respectively), each with leading edge sweep angles of 45 degree , 50 degree , 60 degree and 70 degree , were tested. The measurements, carried out at Mach numbers of 1. 4, 1. 6, 1. 8, 2. 0, 2. 5, and 3. 0, included oil flow visualisations (on both sets of wings) and static pressure distributions (on the thicker wing only). In addition, a 60 degree sweptback delta wing with a normal angle of 40 degree was also tested. The tests on this wing included both oil flow visualisations and static pressure measurements. From these and other existing measurements, the leeside flows have been classified into nine distinct types. These types of flow have been displayed in a plane of Mach number and angle of attack normal to the leading edge.