LOW-SPEED WIND-TUNNEL INVESTIGATION OF A WINGLESS JET VTOL TRANSPORT MODEL

摘要

A wind-tunnel investigation has been made of the static stability and lift and drag characteristics of a small-scale model which represented a wingless turbojet-powered vertical-take-off-and-landing (VTOL) transport airplane, which might have some performance advantage over a winged airplane for cruise at high subsonic speeds at very low altitudes. The model consisted of a fuselage with conventional tail surfaces at the rear and with 12 simulated jet engines near the center which could be tilted from a horizontal attitude for normal forward flight to a vertical attitude>for hovering flight. The investigations consisted of power-off and power-on longitudinal stability and lift and drag tests and power-off lateral stability tests. The results of the investigation showed that satisfactory static longitudinal stability characteristics could be obtained and that a maximum trimmed lift-drag ratio of about 5 could be obtained at a lift coefficient of about 0.15 which is approximately the lift coefficient for a Mach number of 0.6 at sea level for a full-scale airplane of the type represented by the model.