An experimental and theoretical investigation of the effect of nonmetric over-the-wing nacelles on wing-body aerodynamics

Drag reduction benefits due to blowing the jet exhausts over the wing for a transport-type wing-body configuration were investigated in the Langley 16-foot transonic tunnel. A combination of a wing-body model and a powered-nacelle test rig was tested at Mach numbers of 0.50 and 0.80 at angles of attack from -2 degrees to 4 degrees and jet total-pressure ratios from jet off to 3 or 4 (depending on Mach number) for a variety of nacelle locations relative to the wing. The experimental results were compared with the predictions obtained from several theoretical techniques. It was concluded that positioning of the nacelles (nonmetric) can have large effects on the wing-body drag. Some positions yielded higher drag than the baseline position, whereas others yielded lower drag than the baseline position. The theoretical method which utilized a quasi-vortex-lattice for the wing and wing-jet interaction in combination with a jet entrainment model gave generally reasonable predictions of the drag increments.