基于面积律概念的超音速减阻设计方法

A More Efficient Design Method for Supersonic Drag Reduction

在分析基于线性理论的跨、超音速面积律设计方法的优点与不足的基础上,依据CFD方法在流场分析和气动力计算方面的优势,提出了面积律概念指导下的CFD技术减阻设计方法。与传统的超音速面积律方法比较,该方法给出了面积律作用的物理原因,直接建立了横截面积分布与流场品质之间联系,修形设计目标直观明确、减阻效果明显,且设计工作量小,具有进行复杂外形超音速减阻设计的能力。算例表明,该方法对复杂外形的强约束减阻设计具有很好的适应性,对现役飞机改型是一种工程上简单、易行、外形改动小、结果可靠的修形设计方法;对新型飞机设计具有方案颠覆性小、周期短的优点。具有良好的工程实用性和可操作性。

The traditional operation of supersonic area rule is, in our opinion, not efficient in supersonic drag reduction. Now we propose a new way of operation that we believe is much more efficient. In the full paper, we explain our new way in detail; in this abstract, we just list the two topics of our explanation： （1） the design method of area rule; （2） the three steps of supersonic drag reduction design based on the concept of area rule; the first step is that CFD （Computational Fluid Dynamics） is used to analyze the flow field of the configuration and to calculate the aerodynamic characteristics; the second step is that the supersonic characteristic theory is used to find out the local figuration that induces the bad quality of the flow field and then such local figuration is redesigned according to the area rule; the third step is that the drag reduction is verified by using CFD. Finally we compare our new way of operation of area rule with the traditional way of operation through the redesign of a certain canard configuration. The numerical method based on the Euler equations is chosen to calculate the aerodynamic characteristics. Fig. 4 in the full paper shows the two cross-sectional area distributions： SDF （small dorsal fin） distribution obtained by traditional way and RSDF （retral small dorsal fin） distribution obtained by our new way. Fig. 2 in the full paper shows that zero-lift supersonic drag reduction of RSDF is better than that of SDF. Our new way of operation of area rule is not only more efficient for redesign, but also we expect it to be more efficient for supersonic drag reduction of new aircraft.