短钝锥上升器的超声速阻力特性仿真和优化

Simulation and Optimization of Supersonic Drag Characteristics of Blunt Cone Ascender

降低激波阻力是火星上升器气动优化的重要目标。采用计算流体力学(Computational Fluid Dynamics, CFD)方法,针对典型短钝锥上升器外形的超声速阻力特性开展研究,在长细比0.42的设计约束下,比较了13组母线外形的零升阻力,并讨论了纵向静、动稳定性。研究表明:在设计约束下,球鼻大且锥面平缓的钝头形状有低阻特性,原因是超声速气流在经过球鼻后连续膨胀减压,形成了球鼻处小范围的高压区和锥面处大范围的低压区,使整体阻力下降;短钝锥外形有较高静稳定性和呈现临界动稳定性。

Reducing shock drag is an important objective of the aerodynamic optimization of Mars ascenders. The CFD(Computational Fluid Dynamics) method is used to study the supersonic drag characteristics of a typical blunt cone ascender. Under the design constraints of slenderness ratio of 0.42, 13 groups busbar shape set of zero-lift drag are compared, and the longitudinal static and dynamic stability are discussed. The research results show that, under the design constraints, the blunt shape with large bulbous and a gently sloped conical surface has low drag characteristics. The reason is that, after passing through the bulbous, the supersonic airflow is continuously expanded and depressurized, and are formed a small area of high pressure at the bulbous nose and a large area of low pressure at the cone surface, which reduce the overall drag. Moreover, the shape of blunt cone has higher static stability and critical dynamic stability.