Abstract:
Tests have been made at a Mach number of 4.03 and Reynolds number of 3.4 million on two families of models, consisting of delta wings with underslung half-Cone bodies. The wing sweepback angles were 75° and 80°, and the appropriate cone semi-vertex angles tested were 4°, 10° and 13° for the larger wing and 4°, 6.7° and 10° for the smaller wing. The surface distributions were measured at four chordwise stations on all models for incidences between 0° and 9.6° and analysed to provide information on the influence of the wing on the cone flow, and conversely the cone influence on the wing lower- and upper-surface flow. It was found that near the wing-body junction the resultant pressure was close to that obtained by superposing the wing and body flow fields. On the most windward generator of the cone the wing influence is negligible. For small incidences, the pressure changes due to the cone on the exposed wing undersurface may be predicted by exact cone theory; at all incidences, these pressure changes are linked to the pressures developed on the cone surface near the junction. The pressure increments were integrated to give the lift and pressure drag acting on the models (base drag excluded) and from these quantities the lift/drag ratio may be found. The highest value of this occurs for the isolated wings, but the ratio is sensitive to model attitude. The combinations which have a large body develop a smaller maximum lift/drag, but the variation of this ratio with incidence is much smaller. The present tests are preliminary ones in a programme aimed at obtaining a fuller understanding of the flow about lifting vehicles at high supersonic speeds.
