| Popis: |
The shock drag of a sweptback wing originates mainly from the wing roots, where the " S " shaped wing streamlines are constrained to move along the side of the fuselage. An accurate method of calculating the free-stream shape of these streamlines was developed and used to design a model of a fairing for an EC. 1240 wing swept back 65° from a flat plate. This fairing reduced considerably the wing root shock drag at M = 1.73, as determined by pressure plotting. With the fairing removed, the flat plate-wing junction gave pressures and supersonic shock drag corresponding to a similar but unswept wing, thus demonstrating the importance of fairing the wing root. A wingroot vortex was observed in all cases without the fairing but was never observed with the fairing in place. The fairing was equally effective in reproducing subsonic flow patterns a t supersonic speeds over the whole incidence range tested (—4° to + 4 ° ) . The tests were carried out in the Ordnance Aerophysics Laboratory Lone Star tunnel, Daingerfield, Tex., at a Reynolds Number of 4.24 million. Model strength at this high Reynolds Number prevented tests beyond 4° incidence. I t is shown that the theory advanced in this report would also apply to a fairing between a swept-wing fuselage of any cross section, a t any speed from M — 0 to M — Mcr. sec A. |
