关键词: 翼型, 翼型型线, 中弧线函数, 厚度函数, 解析构造法

Abstract: It is important that the geometric shape of a complex airfoil contour be expressed
by an analytic formula. In this paper, the method to construct airfoil contour by analytic functions
is discussed. Joukowsky airfoil contour function is simplified to a straightforward expression with
mean camber function and thickness function. Many airfoil contours can be constructed by
redefining and transforming the coefficients and indexes in the expansion, and more complex
airfoil contours can be obtained through separating and resetting the upper and lower contours.
Also, the contour function of any airfoil with smooth trailing edge is obtained by adding an
independent thickness function. It is shown that a complex airfoil contour can be expressed by an
analytic function with limited parameters which have clear geometric meaning, and can be used to
adjust the local shape easily. As an example of application, the paper also gives a method to
construct analytic function of blade with an airfoil contour, a chord and a twist functions.

Key words: airfoil profile, airfoil contour, mean camber function, thickness function;
analytic construction method