![]() The drag due-to lift component is calculated using lift-analysis programs. This average is over all azimuthal angles. ![]() The bodies of revolution are defined by the cuts through the aircraft made by the tangent to the fore Mach cone from a distant point of the aircraft at an azimuthal angle. The zero-lift wave drag component can be obtained based on the supersonic area rule which tells us that the wave-drag of an aircraft in a steady supersonic flow is identical to the average of a series of equivalent bodies of revolution. At the boundary wall, the normal component of velocity is zero therefore an infinitesimal area exists where there is no slip. The skin-friction component is derived from the presence of a viscous boundary layer which is infinitely close to the surface of the aircraft body. Where C DO is the sum of C (D,friction) and C D,thickness, and k for supersonic flow is a function of the Mach number. Therefore, the Drag coefficient on a supersonic airfoil is described by the following expression:Ĭ D = C D,friction + C D,thickness + C D,liftĮxperimental data allow us to reduce this expression to: The wave drag due to the thickness (or volume) or zero-lift wave drag.Lift and drag Īt supersonic conditions, aircraft drag is originated due to: The airfoils' thickness, camber, and angle of attack are varied to achieve a design that will cause a slight deviation in the direction of the surrounding airflow. A rounded edge would behave as a blunt body in supersonic flight and thus would form a bow shock, which greatly increases wave drag. This shape is in contrast to subsonic airfoils, which often have rounded leading edges to reduce flow separation over a wide range of angle of attack. The sharp edges prevent the formation of a detached bow shock in front of the airfoil as it moves through the air. Supersonic airfoils generally have a thin section formed of either angled planes or opposed arcs (called "double wedge airfoils" and "biconvex airfoils" respectively), with very sharp leading and trailing edges. The need for such a design arises when an aircraft is required to operate consistently in the supersonic flight regime. JSTOR ( January 2019) ( Learn how and when to remove this template message)Ī supersonic airfoil is a cross-section geometry designed to generate lift efficiently at supersonic speeds.Unsourced material may be challenged and removed.įind sources: "Supersonic airfoils" – news Please help improve this article by adding citations to reliable sources. ![]() This article needs additional citations for verification. ![]()
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