Induced drag is the result of wingtip vortex produced from generating lift by finite wing. It is one of the main drags that an aircraft wing encounters during flight. It hampers aircraft performance by increasing fuel consumption and reducing endurance, range and speed. Winglets are used to reduce the induced drag. They weakens wingtip vortex and thus reduces induced drag. This paper represents the experimental investigation to reduce induced drag using winglet at the wingtip. A model of tapered wing with curved trailing edge (without winglet) as well as two similar wings with blended winglet and double blended winglet are prepared using NACA 4412 aerofoil in equal span and surface area. All the models are tested in a closed circuit subsonic wind tunnel at air speed of 108 km/h (0.09 Mach). Reynolds number of the flow is 2.28 × 10~5 on the basis of average chord length of the wings. The point surface static pressures at different angles of attack from -4° to 24° are measured for each of the wing and winglet combinations through different pressure tapings by using a multi-tube water manometer. From the static pressure distribution, lift coefficient, drag coefficient and lift to drag ratio of all models are calculated. From the analysis of calculated values, it is found that both winglets are able to minimize induced drag; however, the tapered curved trailing edge span with blended winglet provides better aerodynamic performance.
展开▼
机译：诱导阻力是由有限翼产生升力产生的Wingtip涡流的结果。它是飞机翼在飞行期间遇到的主要拖延之一。通过提高燃料消耗并降低耐力，范围和速度，妨碍飞机性能。小翼用于减少诱导的拖动。它们削弱了Wingtip Vortex，从而减少了诱导的阻力。本文代表了在WingTip中使用小翼减少诱导拖曳的实验研究。使用Naca 4412 Aerofil在相等的跨度和表面积中，使用Naca 4412翼片制备弯曲后缘（没有翅翼）以及两个类似的翅膀的锥形翅膀的模型以及两个类似的翅膀。所有型号在108 km / h（0.09马赫）的空气速度下在闭路亚态风洞中进行测试。 Reynolds流量的数量是翅膀平均弦长的2.28×10〜5。通过使用多管水压力计通过不同的压力胶带测量来自-4°至24°不同的攻击角度的点表面静电压力。从静态压力分布，计算升力系数，拖曳系数和升力到所有型号的拖动比。从计算值的分析中，发现两个小翼都能够最大限度地减少诱导拖动;然而，锥形弯曲后边缘跨度与混合的翼片提供更好的空气动力学性能。
展开▼
