摘要
为了能够方便快捷的设计和修改翼型,采用两段椭圆弧来构造翼型的中弧线,并推导了描述中弧线的方程式。用该方法构造的中弧线光滑连续,且不存在拐点。选用现有翼型的厚度分布,与中弧线分布函数进行叠加,并引入厚度比例因子来实现对厚度的调整,最终得到了一种基于双椭圆弧型中弧线的翼型设计方法,称之为DEA(double ellipse arcs)翼型。选用Clark-Y翼型作为基础翼型,设计了多款DEA翼型,并利用X-foil软件对翼型气动性能进行求解,分别研究了最大相对弯度、最大弯度相对位置、最大相对厚度以及翼型中弧线的形状因子对翼型气动性能的影响。研究表明:增加最大相对弯度,可以提高翼型的升力系数,同时使翼型的升阻特性得到一定的改善;最大弯度位置前移,可以提高翼型在小攻角下的升力系数,同时增加翼型高效升阻比的攻角范围;增加最大相对厚度可以提高翼型的最大升力系数,以及增大失速攻角,同时,高效升阻比的攻角范围也随着翼型最大相对厚度的增大而增加;中弧线前、后缘形状因子对翼型气动性能的影响相对较小。
Airfoil,as a product of aviation technology,has been widely used in the design of fluid machinery products.The aerodynamic characteristics of airfoils are a key factor in determining the performance of fluid machinery.When the existing airfoils are not able to meet the engineering requirements,it is necessary to redesign or trim the original airfoils.In this research,2 ellipse arcs were used to form the mean camber line of the airfoil,and the corresponding equation was deduced.This equation controls the shape of the mean camber line by changing the maximum camber and the relative position of maximum camber,and adjusts the local shape by changing the 2 shape factors of the mean camber line.The mean camber line constructed by this method is smooth and continuous,and there is no knee point.Then the thickness distribution of the existing airfoil was superposed with the distribution function of mean camber line,and a thickness scale factor was introduced to adjust the thickness distribution.Ultimately,the design method for a series of airfoils based on mean camber line of double ellipse arcs is achieved,which is called DEA（double ellipse arcs） airfoil.The airfoil profile function constructed by this method has definite physical meaning,simple and reliable,and it is easy to realize serialization.In order to study the influence of airfoil characteristic parameters on aerodynamic performance of the DEA airfoil,the Clark-Y airfoil was taken as the basic airfoil,and a number of DEA airfoils were designed using the thickness distribution of the Clark-Y airfoil.Then the aerodynamic characteristics of the designed airfoils were solved by the X-foil software to study the influence of the maximum camber,the relative position of the maximum camber,the maximum thickness and the shape factors of the mean camber line on the DEA airfoil aerodynamic performance.There are 5 characteristic parameters in all that influence the shape of the DEA airfoil.We selected one of the 5 characteristic parameters as variable and fixed the other
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2018年第2期40-46,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金(11172243)
陕西省科技统筹创新工程计划(2011KTCQ01-02)
关键词
设计
翼型
数值分析
中弧线
椭圆弧
design
airfoils
numerical analysis
mean camber line
double ellipse arcs
