EFFECTS OF WING POSITION AND FUSELAGE SIZE ON THE LOW-SPEED STATIC AND ROLLING STABILITY CHARACTERISTICS OF A DELTA-WING MODEL

摘要

An investigation was made to determine the effects of wing position and fuselage size on the low-speed static and rolling stability characteristics of airplane models having a triangular wing and vertical tail surfaces.nFor the longitudinal-stability case, the results indicated that, for all wing positions, as the fuselage size was increased the maximum lift coefficient decreased. Also, for a given fuselage size, the maximum lift coefficient increased as the wing position was changed from low to high.nFor the lateral-stability case, the results indicated an increase in the vertical-tail lift-curve slope as well as an increase in the effective dihedral with an increase in fuselage size. Both these effects could be calculated with good accuracy by using available theory. As indicated by both available theory and results of previous investigations, the effective dihedral at low angles of attack caused by wing-fuselage interference changed sign as the wing position was changed from low to high. Moving the wing from the low to the high position caused the vertical-tail contribution to the directional stability to decrease at low and moderate angles of attack. At high angles of attack, all the configurations investigated became directionally unstable. However, the low-wing—large-fuselage (fineness-ratio-6) configuration maintained directional stability to an angle of attack above that which corresponds to maximum lift.nFor the rolling-stability case, the results generally indicated very little effect of both wing position and fuselage size.