Reynolds number at which the airfoil performance is evaluated.Īirfoil’s thickness in fraction of chord length.Īirfoil’s Drag Divergence Mach number (required for high subsonic aircraft, transonic aircraft, and supersonic aircraft) It is important that you have them all completely, so, you can go through all part of this tutorial without any obstacle. it is also recommended that you understand the basic concept of airfoil aerodynamics first to make this tutorial easier for you.īefore taking further steps in this tutorial, you should prepare the items/data listed below. If you don’t have aerospace engineering background. If you don’t have it, you need to search the internet for your airfoil’s aerodynamic characteristics or obtain it yourself by using CFD software. It is also assumed that you already have your own airfoil shape and its aerodynamic characteristics (lift polar, drag polar, and moment polar, etc).
#Supersonic airfoil windows
This tutorial was made based on X-Plane 9’s Airfoil-Maker with Windows Vista 32 operating system. In this tutorial, it is assumed that you are using the same version of X-Plane’s Airfoil-Maker and you are familiar with basic computer file operation.
#Supersonic airfoil how to
The Oblique shock in supersonic flow moves from the centre of the airfoil in subsonic flow to the trailing edge in supersonic flow, this effect increases drag, the effect is known as wave drag and it can affect lift.In this tutorial, you will learn how to create custom airfoil for your aircraft in X-Plane by using Airfoil-Maker. The figure below shows a supersonic airfoil with angle of attack (θ), as the angle of attack increases the lift generated increases, up until the stall point (separation point well forward of the trailing edge). The presence of shock waves, along with the compressibility effects of high-velocity fluids, is the central difference between supersonic and subsonic aerodynamic flow. This causes a greater pressure under the airfoil and therefore creates lift (cjl, 2012). Pressure difference in supersonic flight is generated by shocks at the airfoil’s leading edge (Figure “oblique shock”), the shock going down (angle of attack dependant) is stronger than the shock going up, because of this the pressure jump across the shock going down from the leading edge is larger than the one across the shock going up. The lift, however, is still generated by the pressure differences but in the case of supersonic flow it is generated in a different way (cjl, 2012). Supersonic flows have high viscous dissipation, the flow as a whole is no longer inviscid, and is also compressible. Bernoulli’s Principle simply describes the pressure along a streamline as a function of the local velocity, assuming an inviscid, incompressible and irrotational flow. In supersonic flight, lift is generated only by the angle of attack. In subsonic flight the wing generates lift by means of accelerating the flow around the top surface of the airfoil, this is achieved by altering the chord, upper & lower camber, curvature and the angle of attack in order to produce an area of lower pressure above the airfoil. It has turned out to be an interesting area due to the difference in lift mechanisms and flow patterns. My last post on subsonic lift got me thinking about the possible differences with supersonic lift.
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