Wing Twist

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  Wing twist is of two types named as geometric twist and aerodynamic twist:- Geometric Twist Different angles of attack at wing root and tip. Wash in Tip chord has a higher angle of attack than that of root chord. Wash out Angle of attack at tip is lower than that at wing root. It is useful in reducing tip vortices. Aerodynamic Twist Difference between zero-lift lines of airfoils at wing root and near the tip. Airfoils at root and near the tip have different zero lift angles of attack.
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How to draw Airfoils ?

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Airfoils are rather simple geometrical objects as they are nothing but a curve drawn on a flat plane of paper, defined by coordinates usually by two columns namely, x and y. They define airfoil as locus of points where each point is defined by a set of x and y coordinates. It can be created of 50 or 100 points depending on the chord length decided as per the requirements.

To draw airfoils, you have various tools available like:-

 1.  Software 

They work on the airfoil coordinates available in dat file and use it to plot airfoil on the screen which can be printed afterwards. Some of the software available out there include Catia, Solidworks, AutoCAD, Xfoil and Concord (conversion of airfoil coordinates). 



2.  Online plotter 

It includes various websites having with them airfoil database which is available for all, you can just select airfoil needed from the list or else you can enter the details like LE radius, chord, camber to plot airfoil which can be downloaded also. Some of the providers include Airfoil Tools , Wind & Wet.



3.  Manual Drawing 

It is a handy way of sketching airfoils on a rough paper, similar to drawing of coordinate graphs in which you mark the points on the X-Y plane as per their coordinates and at last join all the points. The locus of all points give you the airfoil required. 






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