基于可变马赫数锥形流场的定平面形状乘波体设计方法研究

RESEARCH ON DESIGN METHOD OF PLANFORM-CUSTOMIZED WAVERIDER FROM VARIABLE MACH NUMBER CONICAL FLOW

传统乘波体设计方法设计状态单一,乘波体偏离设计点状态时高升阻比性能优势难以保持,限制了乘波体在宽速域气动布局设计中的应用.文章从密切锥乘波体理论出发,通过在不同密切面内布置不同马赫数的锥形流场,提出基于可变马赫数流场的定平面形状乘波体设计方法,根据给定前缘型线生成不同展向马赫数分布的基准外形.使用计算流体力学技术分析流场激波结构以及升阻力性能和纵向稳定性,并与传统使用固定马赫数锥形流场的乘波体外形作比较,探索这种定平面形状乘波体在高超声速范围内的宽速域特性.结果表明,基于可变马赫数流场的定平面形状乘波体设计是可行的,可以有效扩大设计空间;在高超声速阶段的宽速域范围内,可变马赫数乘波体具有均衡的升阻比和容积率;但可变马赫数基准流场对纵向稳定性的影响很小.比较等容积、同样平面形状的固定马赫数乘波体,发现在高超声速阶段,可变马赫数乘波体的宽速域升阻性能没有明显优势.

The traditional waverider design method has a single design state,and the the aerodynamic performance advantage of high lift-drag ratio is difficult to maintain when the waverider deviates from the design point state,which limits the application of the waverider in wide-speed aerodynamic configuration design.In this paper,based on the waverider design theory of the osculating-cone treatment,by employing the conical flows with differ-ent Mach numbers in different osculating planes,the planform-customized waverider design from variable Mach num-ber flows is proposed based on the geometric design relations in the osculating-cone method,and the double swept waveriders with different spanwise Mach number distribution were generated,which shared the same customized leading edge curve.Computational fluid dynamics techniques were employed to analyze the shock wave structure of flow field,aerodynamic forces and longitudinal stability of the waveriders.Compared with conventional waveriders using fixed conical flows,the wide-speed performances of this kind of planform-customized waverider were explored in hypersonic stage.Results showed that the planform-customized waverider design from variable Mach number flows is feasible,enlarging design space efficiently.In the wide-speed range of hypersonic stage,the waverider from varia-ble Mach number flow featured balanced lift-to-drag(L/D)ratio and volume efficiency.However,when the planform shapes were identical,the difference of aerodynamic centers between the variable-Mach-number waveriders and fixed-Mach-number waveriders was significantly slight,indicating that the variable Mach number flows as basis flows had nearly no effect on longitudinal stability.Meanwhile,compared with the fixed-Mach-number waveriders with equal volume and identical planform shape,the wide-speed L/D ratio of the variable-Mach-number waveriders were not su-perior in hypersonic stage.