Wing M E 5 7 8 A i r c r a f t D e s i g n 1 The wing is the most important component of an aircraft’s structure. After all, from the most basic mechanics of flight, the wing is what makes an airplane an airplane, what enables an airplane to fly. An airplane is basically designed about the wing.
Wing Configuration Wings are designed based upon what the aircraft is designed to do. In other words, the airplane’s requirement, function and purpose. In designing wing, we need to consider: the type of aircraft? the operating altitudes of the aircraft (thin atmospheres)? what is the wing loading (W/S)? will the wing carry engines or stores? how much fuel will be stored inside? how fast and how maneuverable will the aircraft need to be? M E 5 7 8 A i r c r a f t D e s i g n 2 Yet again, the “form follows function” principle applies when comes to wing configuration and design. The steps we should follow for designing are: Understand wing's application Select proper wing design Define parameters
Wing Classifications From structural point of view, wing configurations can be classified as: Cantilever wing Braced or strutted wing Nonplanar wing M E 5 7 8 A i r c r a f t D e s i g n 3 From fuselage arrangement point of view, wing configurations can be classified as: High wing Mid wing Low wing From sweep angle viewpoint, wing configurations can be classified as: Zero (negligible) sweep Aft (positive) sweep Forward sweep Variable sweep Oblique sweep
Cantilever and Braced Wings To support lift and the weight of an aircraft, a wing has to be sufficiently rigid and strong. As a consequent, it may be heavy. By adding external bracing, the weight can be greatly reduced. M E 5 7 8 A i r c r a f t D e s i g n 4 All early airplanes were braced wings. Braced wings are wings supported by external structural members. The key advantage of braced wing is low weight. There are two main types of braced wings: Strut braced uses stiff struts to support the wing. A strut can act in compression or tension. Wire braced uses cables to support the wing. Unlike a strut, a wire can act only in tension. It is normal to employ multiple cables to support both compression and tension loads
Braced Wings M E 5 7 8 A i r c r a f t D e s i g n 5 The disadvantage of braced wings is they cause a large amount of drag at higher speeds, and are therefore not used for transonic and supersonic designs. However, NASA Boeing are taking a second look at Braced wing that are low drag for their future aircraft design. Strut braced wing has the potential of reaching even higher aspect ratio for even greater fuel savings. Braced wings are today used mostly for small aircraft and low speed applications.
Cantilever Wing M E 5 7 8 A i r c r a f t D e s i g n 6 Cantilevered wing is self-supporting. All the structure is buried under the aerodynamic skin, giving a clean appearance with low drag. It is the natural choice for large aircraft and high speed applications.
Wing Configuration Advantage of High-Wing and Low-Wing Aircraft Visibility :
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- Spring '19
- Aerodynamics, Wing design, Planform, Aircraft Design