Experiments at M = 1.41 on a thin, conically-cambered elliptic cone of 30 degrees semi-vertex angle

Abstract

Pressure-plotting and strain-gauge balance tests have been made at a Mach number of 1.41 on a conically cambered cone of 30° semi-vertex angle, and with a ratio of the major to the minor axis of its cross-section equal to 11.55. The camber line was designed for a CL of 0.3 by the method of Ref. 2. The upper-surface pressure distribution was found to be strongly influenced by the boundary-layer state in the leading-edge region, and when this was turbulent good agreement with the theoretical spanwise loading was obtained at the design CL, though this was obtained at a somewhat higher incidence than the design value. The flow development with incidence for both boundary-layer states is discussed with the aid of oil-flow patterns. The results for the cambered cone are compared with those obtained in 1954 for a corresponding uncambered elliptic cone. Both cones have the same normal-force curve slope; the cambered cone has a higher minimum drag coefficient, but a smaller lift-dependent drag factor. At the design C L the drag of the two models is the same.