Abstract: Class function/shape function transformation technique(CST) was improved and used to design the leading edge of the controlled diffusion airfoils. This method removes the leading edge curvature discontinuities, eliminates the leading-edge spikes under the design states, and then improves the aerodynamic performance significantly. Different leading-edge shapes with no curvature discontinuities were achieved using different shape function. Although they have the same minimum loss, the available incidence range is quite different. Studies show that it is caused by the different development process of the leading edge spikes under the off-design conditions. Too large spikes could thicken the early suction surface boundary layer rapidly or even cause premature transition.

Key words: CST methodology;Controlled diffusion airfoil;Leading-edge geometry;Available incidence range

摘要： 采用改进的形状函数变换技术(CST)造型方法对一个可控扩散叶型(CDA)的前缘进行优化设计,实现了叶片前缘与叶身连接之间的曲率连续,消除了设计状态下叶片前缘速度尖峰,使得叶片的气动性能得到了显著改善。利用不同的形状函数生成不同的曲率连续前缘,叶型的最小损失相同,可用攻角范围的差别却很大。研究表明,这是由于前缘速度尖峰在非设计工况下的发展变化过程不同造成的。过强的前缘尖峰会导致附面层迅速增厚甚至提前转捩。 

关键词: CST造型方法;可控扩散叶型(CDA);前缘形状;可用攻角范围 