Abstract: An experimental research report on joined wing aircraft is presented. The experiments are conducted in a low-speed wind tunnel. A joined wing aircraft has a general arrangement which combines swept-aft front wing and swept-forward rear wing joined at 60%- 100% of the front wing span, a fuselage, and a vertical fin. The wings form a diamond shape in both planform and in front view. The longitudinal and lateral-directional aerodynamic characteristics of the joined wing aireraft are discused. In addition, the effects of changes in geometric parameters are also pointed out. The Low-speed wind tunnel tests have shown that the joined wing provides the following advantages over a comparable wing-plus-tail system: lower induced drag, higher lift-to-drag ratio and better stall characteristics.The changes in dihedral of front wing and cathedral of rear wing have little effect on longitudinal aerodynamic characteristics but large effect on lateral-directional characteristics. The pitching characteristics is improved when the sweep-back of outboard of front wing is reduced.

Key words: joined wing aircraft, wind tunnel tests, aerodynamic characterstics