Читать книгу Flight Theory and Aerodynamics - Joseph R. Badick - Страница 89

The terminology used to discuss an airfoil is shown in Figure 3.14:

1 Chord line is a straight line connecting the leading edge and the trailing edge of the airfoil.

2 Chord is the length of the chord line. All airfoil dimensions are measured in terms of the chord.

3 Mean camber line is a line drawn equidistant between the upper surface and the lower surfaces.

4 Maximum camber is the maximum distance between the mean camber line and the chord line. The location of maximum camber is important in determining the aerodynamic characteristics of the airfoil.

5 Maximum thickness is the maximum distance between the upper and lower surfaces, and its location of maximum thickness will also be important when determining aerodynamic characteristics.

6 Leading edge radius is a measure of the sharpness of the leading edge. It may vary from zero for a knife‐edge supersonic airfoil to about 2% (of the chord) for rather blunt leading edge airfoils.