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A supercritical aerofoil (supercritical airfoil in American English) is an airfoil designed primarily to delay the onset of wave drag in the transonic speed range. Supercritical airfoils are characterized by their flattened upper surface, highly cambered ("downward-curved") aft section, and larger leading-edge radius compared with NACA 6-series ...
Two of the important technological advancements that arose out of attempts to conquer the sound barrier were the Whitcomb area rule and the supercritical airfoil. A supercritical airfoil is shaped specifically to make the drag-divergence Mach number as high as possible, allowing aircraft to fly with relatively lower drag at high subsonic and ...
For example, the NACA 2412 airfoil has a maximum camber of 2% located 40% (0.4 chords) from the leading edge with a maximum thickness of 12% of the chord. The NACA 0015 airfoil is symmetrical, the 00 indicating that it has no camber. The 15 indicates that the airfoil has a 15% thickness to chord length ratio: it is 15% as thick as it is long.
It is used for near-supersonic flight and produces a higher lift-to-drag ratio at near supersonic flight than traditional airfoils. Supercritical airfoils employ a flattened upper surface, highly cambered (curved) aft section, and greater leading-edge radius as compared to traditional airfoil shapes. These changes delay the onset of wave drag.
After World War II, NACA research began to focus on near-sonic and low-supersonic airflow.After considering the sudden drag increase which a wing-fuselage combination experiences at somewhere around 500 mph (800 km/h), Whitcomb concluded that "the disturbances and shock waves are simply a function of the longitudinal variation of the cross-sectional area" – that is, the effect of the wings ...
Schemes have been devised to define airfoils – an example is the NACA system. Various airfoil generation systems are also used. An example of a general purpose airfoil that finds wide application, and pre–dates the NACA system, is the Clark-Y. Today, airfoils can be designed for specific functions by the use of computer programs.
Most people enter military service “with the fundamental sense that they are good people and that they are doing this for good purposes, on the side of freedom and country and God,” said Dr. Wayne Jonas, a military physician for 24 years and president and CEO of the Samueli Institute, a non-profit health research organization.
For example, consider that at Mach 1.3 the angle of the Mach cone generated by the nose of the aircraft will be at an angle μ = arcsin(1/M) = 50.3° (where μ is the angle of the Mach cone, also known as Mach angle, and M is the Mach number). In this case the "perfect shape" is biased rearward; therefore, aircraft designed for lower wave drag ...