Its design allows the wing to maintain high performance levels at speeds closer to Mach 1 than traditional counterparts.īetween 19, the British aerospace manufacturer Hawker Siddeley Aviation, based in Hatfield, England, designed its own improved airfoil profiles, which were sometimes referred to as rooftop rear-loaded airfoils. Aerodynamicists determined that, by appropriately shaping the airfoil used, the severity of these problems could be greatly reduced and allow the aircraft to attain much higher speeds this is the basis of the supercritical wing. Supersonic airflow over the upper surface of the traditional airfoil induced excessive wave drag, as well as a form of stability loss known as Mach tuck. ĭuring the 1950s and 1960s, a number of different high speed research aircraft equipped with conventional airfoils repeatedly encountered difficulties in breaking the sound barrier, or even reaching Mach 0.9. The aviation authors Ernst Heinrich Hirschel, Horst Prem, and Gero Madelung have referred to the supercritical airfoil as being of equal importance, in terms of aerodynamics, as the innovation of the swept wing to high speed aircraft. Kawalki's airfoil shapes were identical to those subsequently produced by the American aerodynamicist Richard Whitcomb. Testing of these airfoils was reported by B. Kawalki at Deutsche Versuchsanstalt für Luftfahrt Berlin-Adlershof designed a number of airfoils characterised by elliptical leading edges, maximal thickness located downstream up to 50% chord and a flat upper surface. The supercritical airfoil was first suggested by aerodynamicists in Germany during the Second World War. Accordingly, techniques learned from studies of the original supercritical airfoil sections have been used to design airfoils for several high-speed subsonic and transonic aircraft, from the Airbus A310 and Boeing 777 airliners to the McDonnell Douglas AV-8B Harrier II jumpjet. In America, the aerodynamicist Richard Whitcomb produced supercritical airfoils identical to Kawalki's earlier work these were used to devise a supercritical wing that was, in turn, incorporated into both civil and military aircraft.
In particular, Hawker Siddeley Aviation designed a number of advanced airfoils that were, amongst other programmes, incorporated into the Airbus A300. Following the end of the conflict, multiple nations continued research into the field, including Germany, the United Kingdom, and the United States. Kawalki, who designed a number of airfoils during the Second World War. The origins of the supercritical airfoil can be traced back to the German aerodynamicist K. A. Supercritical airfoils are designed to minimize this effect by flattening the upper surface of the wing. The formation of these shockwaves causes wave drag. As the speed of the aircraft approaches the speed of sound, the air accelerating around the wing reaches Mach 1 and shockwaves begin to form. Both the thickness distribution and the camber of the wing determine how much the air accelerates around the wing. Standard wing shapes are designed to create lower pressure over the top of the wing. 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 laminar airfoil shapes. The supersonic flow over a supercritical airfoil terminates in a weaker shock, thereby postponing shock-induced boundary layer separation.Ī supercritical airfoil ( supercritical aerofoil in British English) is an airfoil designed primarily to delay the onset of wave drag in the transonic speed range. Illustrated are: A – supersonic flow region, B – shock wave, C – area of separated flow.
NACA SUPERSONIC AIRFOIL GENERATOR FREE
Conventional (1) and supercritical (2) airfoils at identical free stream Mach number.
0 kommentar(er)
