给定前缘线平面形状的密切锥乘波体设计方法

OSCULATING-CONE WAVERIDER DESIGN BY CUSTOMIZING THE PLANFORM SHAPE OF LEADING EDGE

乘波体因其高超声速阶段的高升阻比性能成为目前研究的热点,但其本身的诸多性能缺陷限制了其在工程中的实际应用.密切锥乘波体设计是目前应用较广的乘波体外形设计方法,具有较高的灵活性和生成效率.本文以弥补乘波体性能缺陷,提高乘波体设计灵活性为目的,拓展了密切锥乘波体设计方法,推导设计方法中激波出口型线、流线追踪起始线与平面形状轮廓线之间的几何关系,并使用一个微分方程组给出了具体的数学表达,奠定了定平面形状乘波体设计的理论基础.通过介绍此微分方程组的数值求解过程,并分析应用此关系的注意事项,本文提出了给定前缘线平面形状的密切锥乘波体设计方法.根据此设计几何关系,以渐变前缘、弯曲前缘和双后掠等为例生成定平面形状乘波体外形,结合计算流体力学方法分析这几类外形的流场,通过流场分布与设计曲线的比较,说明通过此方法设计得到的乘波体外形保持了高超声速状态的乘波特性,并可以方便的控制平面形状,为提高乘波体的设计灵活性、改善性能缺陷提供了新的途径.

The waverider has been the current research focus because of high lift to drag ratio in hypersonic state, while some deficiencies of waverider limit its practical application in engineering. Osculating-cone method is one of the most widely applicable waverider design methods for engineering, yielding much flexibility and efficiency. In order to remedy some of the deficiencies and improve the flexibility for waverider, the article extends the application of the osculating-cone waverider design method, conducting the geometric relationships among the inlet capture curve, flow capture tube and planform contour line, expressed by a differential equation set. The equation set lays a solid foundation for the planform-controllable waverider design. By introducing the numerical solving strategy for the differential equation set, combining with some solving tips, the osculating-cone waverider design by customizing the planform shape of leading edge is proposed. Three validation cases are generated in the article including the gradually varied leading edge,"S" leading edge and double swept planforms from the osculating-cone waverider by customizing the planfrom shape of the leading edge. Using computational fluid dynamics method, the flow fields of these three configurations are calculated and analyzed. Results suggested that the hypersonic wave-riding performance maintenances for the waverider since the shock wave obtained from CFD matches well with the design curve and high lift to drag ratio is remained as traditional waverider. The method and the CFD results indicate that it permit us to customize the planform of waverider conveniently and efficiently. The geometric relationships expressed by a differential equation set provide a novel idea to improve the flexibility and remedy some of the deficiencies of waverider.