高压捕获翼构型的跨流域气动特性

Aerodynamic characteristics of high-pressure capturing wing configuration in multi-regime

  • 摘要: 高压捕获翼(HCW)构型是一种满足高速飞行器高容积、高升力、高升阻比的设计需求的新型气动布局。最近研究表明,HCW构型能够提高飞行器在连续流区的升力和升阻比,缓解飞行器设计中高容积率与高升阻比间的矛盾。为探究该气动布局在过渡流域(70~100 km)的气动特性,以一种楔—平板组合的高压捕获翼原理性构型作为模型,采用直接模拟Monte Carlo (DSMC)方法,详细分析了该模型在典型高超声速条件(马赫数20)下的流场结构和壁面气动力/热分布。结果表明,随着飞行高度增加,稀薄效应增强,机体压缩产生的激波厚度增加,激波边缘逐渐模糊,机体与捕获翼之间的开放通道内出现压力干扰。同时,高压捕获翼表面的摩擦系数迅速上升,气动摩擦成为制约捕获翼构型升阻比的重要因素。针对这一问题,分析了捕获翼材料表面的适应系数对飞行器的气动力/热的影响,结果表明,降低适应系数可以显著减小壁面摩擦和热流量,可通过选用适应系数较小的表面材料进一步提高该类飞行器气动性能。

     

    Abstract: High-pressure capturing wing (HCW) configuration is a novel aerodynamic design for hypersonic vehicles with large volume, high lift, and high lift-to-drag ratio. Recently, comprehensive studies have shown that HCW can effectively improve the lift force and the lift-to-drag ratio of vehicles in the continuous flow regime, and alleviate the contradiction between high volume and high lift-to-drag ratio in aircraft design. In order to explore the aerodynamic characteristics of HCW in different flow regimes (70~100 km), a geometry of wedge-plate combination is taken as a simplified computational model, and the direct simulation Monte Carlo (DSMC) method is employed to investigate the flow field and wall aerodynamic force/heat characteristics under typical hypersonic conditions (Ma = 20). The simulation results show that as the flight altitude increases, the aircraft-induced shock thickness increases, the shock edge gradually becomes fuzzy, and the pressure interference tends to occur in the open channel between the body and HCW. The friction coefficient of HCW increases rapidly with the increase of rarefaction, which becomes an important factor restricting the lift-to-drag ratio of HCW. Furthermore, the effect of accommodation coefficient on the aerodynamic force/heat of the aircraft increases with the rarefaction degree. Reducing the accommodation coefficient can significantly reduce the shear stress and heat flux of HCW, which is an efficient way to reduce the drag and aerodynamic heating, thus can improve the aerodynamic performance.

     

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