SIDE ORDER OF WINGS
SIDE ORDER OF WINGS
In the media, drones have mostly been associated with the military and spying, plus the odd pizza-delivery publicity stunt.
An annual competition in the United Arab Emirates, UAE Drones for Good Award, acknowledges both this dark reputation and that things are changing. Competition finalists this year pitched benefits for unmanned aerial vehicles from conservation support to medical deliveries, as well as farming help.
The Munich-based Quantum-Systems entry was a transition aircraft combining capabilities of a multicopter and fixed-wing model – vertical take-off, plus fast forward flight like a normal plane. Quantum VRT design allows farmers to adopt precise fertilisation strategies via accurate flight-planning software with evaluation of crop conditions, so reducing reliance on fertilisers and boosting yields.
Dubai plans to scale up agriculture drone technology usage in a bid to become self-sufficient in food security by 2030. With 98 per cent imports, the emirate currently outstrips Singapore.
A wing is a type of fin that produces lift, while moving through air or some other fluid. As such, wings have stremilated cross-section that are subject to aerodynamic forces and act as an airfoils. A wing's aerodynamic efficiency is expressed as its lift-to-drag ratio. The lift a wing generates at a given speed and angle of attak can be one to two orders of magnitude greater than the total drag on the wing. A high lift-to-drag ratio requires a significantly smaller thrust to propel the wings through the air at sufficient lift.
Lifting structures used in water, include various foils, including hydrofoil. Hydrodynamic is the governing science, rather than aerodynamics. Applications of underwater foils occur in hydroplanes, sailboats and submarine's.
The wing of a landing BMI AirbusA319-100. The slats at its leading edgeand the flaps at its trailing edge are extended.
Aircraft wings may feature some of the following:
- A rounded leading edge cross-section
- A sharp trailling edge cross-section
- Leading-edge devices such as slats,slots or extensions
- Trailing-edge devices such as flaps or flaperons (combination of flaps and ailerons)
- winglets to keep wingtip vortices from increasing drag and decreasing lift
- Dihedral, or a positive wing angle to the horizontal, increases spiral stability around the roll axis, whereas anhedral, or a negative wing angle to the horizontal, decreases spiral stability.
Aircraft wings may have various devices, such as flaps or slats that the pilot uses to modify the shape and surface area of the wing to change its operating characteristics in flight.
- Ailerons (usually near the wingtips) to roll the aircraft clockwise or counterclockwise about its long axis
- Spoilers on the upper surface to disrupt the lift and to provide additional traction to an aircraft that has just landed but is still moving.
- Vortex generators to help prevent flow separation in transonic flow
- Wing fences to keep flow attached to the wing by stopping boundary layer separation from spreading roll direction.
- Floding wings allow more aircraft storage in the confined space of the hangar deck of an aircraft carrier
- Variable- sweep wing or "swing wings" that allow outstretched wings during low-speed flight (i.e., take-off and landing) and swept back wings for high-speed flight (including supersonic flight)such as in the F-111 Aardvark, the F-14 Tomcat, the Panavia Tornado, the MiG-23, the MiG-27, the Tu-160and the B-1B Lancer warplanes.
Applications
Besides fixed wing, aircraft, applications for wing shapes include:
- Hang gliders, which use wings ranging from fully flexible (paragliders, gliding parachutes), flexible (framed sail wings), to rigid
- Kites, which use a variety of lifting surfaces
- Flying model airplanes
- Helicopters, which use a rotating wing with a variable pitch angle to provide directional forces
- Propellers, whose blades generate lift for propulsion.
- The NASA Space Shuttle, which uses its wings only to glide during its descent to a runway. These types of aircraft are called spaceplanes.
- Some racing cars, especially Formula One cars, which use upside-down wings (or airfoils) to provide greater traction at high speeds
- Sailboats, which use sails as vertical wings with variable fullness and direction to move across water
References
- ^Etymonline.com. Retrieved 2012-04-25.
- ^ Stanford.edu. Retrieved 2012-04-25.
- . Grc.nasa.gov. 2012-04-16. Retrieved 2012-04-25.
- ^ "...the effect of the wing is to give the air stream a downward velocity component. The reaction force of the deflected air mass must then act on the wing to give it an equal and opposite upward component." In: Halliday, David; Resnick, Robert, Fundamentals of Physics 3rd Edition, John Wiley & Sons, p. 378
- ^ "If the body is shaped, moved, or inclined in such a way as to produce a net deflection or turning of the flow, the local velocity is changed in magnitude, direction, or both. Changing the velocity creates a net force on the body". NASA Glenn Research Center. Retrieved 2011-06-29.
- ^ "The cause of the aerodynamic lifting force is the downward acceleration of air by the airfoil..." Weltner, Klaus; Ingelman-Sundberg, Martin archived from on 2011-07-19
- ^ E. V. Laitone, Wind tunnel tests of wings at Reynolds numbers below 70 000, Experiments in Fluids 23, 405 (1997). doi
- ^ "...consider a sail that is nothing but a vertical wing (generating side-force to propel a yacht). ...it is obvious that the distance between the stagnation point and the trailing edge is more or less the same on both sides. This becomes exactly true in the absence of a mast—and clearly the presence of the mast is of no consequence in the generation of lift. Thus, the generation of lift does not require different distances around the upper and lower surfaces." Holger Babinsky How do Wings Work? Physics Education November 2003,
- ^ John D. Anderson, Jr. Introduction to Flight 4th ed page 271.
- ^ 'Supercritical wings have a flat-on-top "upside down" look.' NASA Dryden Flight Research center
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