连翼机低速气动特性实验研究

 连翼机具有前、后机翼,前翼后掠上反,后翼前掠下反;后翼在前翼展60％～100％之间与前翼相连。其前视图和俯视图均构成菱形。在低速风洞中对连翼机进行了纵向及横向测力实验,其中包括前、后翼几何参数改变对气动特性的影响。实验表明,与常规飞机相比连翼机具有如下优点:诱导阻力小,升阻比大且具有较好的失速特性。改变连翼机前翼上反角和后翼下反角对纵向气动特性影响不大,对横向气动特性有明显影响。减小前翼外段的后掠角可使俯仰特性得到改善。

AN EXPERIMENTAL RESEARCH OF LOWSPEED AERODYNAMIC CHARACTERISTICS ON JOINED WING AIRCRAFT

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.