连续流失效对近空间飞行器气动特性的影响

Effects of continuum breakdown on aerodynamics of near space vehicle

  • 摘要: 针对未来近空域大升力面高超声速飞行器的稀薄流动问题,采用NS方程结合滑移模型手段,对高超声速飞行器的简化外形进行了近空域气动特性的计算分析,研究了不同滑移模型的适用性,对比了不同模型下连续流和稀薄流方法所得结果的差异性,给出了稀薄效应对飞行器气动特性影响的定量分析结果。结果表明,本文的计算结果与文献结果一致性较好;相对于热流而言,压力对稀薄效应的敏感性较弱;在较大努森数下,除了滑移模型2以外,其它模型所得热流、压力结果都一致高于DSMC结果,使得防热设计趋于保守;滑移模型2与其它滑移模型相比具有更广泛的适应性;当大升力面梯形翼的飞行高度从50km增加至80km时,滑移方法与无滑移方法所得驻点处峰值热流的偏差量约在1.6%至14.5%之间变化。

     

    Abstract: Hypersonic vehicle suffer rarefied gas effect flying in near space. Attempt has been made to analyse aerodynamics of hypersonic vehicle near space with slip NS methods. The applicability of several different slip boundary conditions has been investigated. The difference between continuum and rarefied predictions for surface properties has been shown. The results show that present results are consistent to reference′s results. Pressure coefficient on the surface is affected by rarefied gas effect slightly, while heat transfer rate is most influenced by that. At Kn=0.25, the surface properties predicted by slip models excepting for Gokcen model tended to be higher than those predicted by DSMC. Gokcen model can be used in an extensive range of Knudsen number compared with others. Peak transfer rate differences for tapered wing with different methods range from over 1.6% for 50km of altitude to almost 14.5% for 80km.

     

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