主管部门: 中国航天科技集团有限公司
主办单位: 中国航天空气动力技术研究院
中国宇航学会
中国宇航出版有限责任公司

壁面温度对高超声速热化学非平衡流动影响的数值模拟

Numerical Simulation of the Effect of Wall Temperatures on Hypersonic Thermochemical Nonequilibrium Flow

  • 摘要: 高超声速飞行器飞行速度快,处在高温高热流的稀薄气体环境。为对流场进行准确的预测,引入非平衡Navier-Stokes方程来考虑热化学反应非平衡流动。通过改变壁面温度分析了流场的激波脱体距离、热通量分布、粒子数分布、气动力等流场特征。结果显示,低温壁面(Tw/Ti = 4)不足以使激波边界层的气体发生足够的膨胀,因此脱体距离最小。随着壁面温度的升高,边界层内的气体膨胀区域增大。激波层内的温度压力急剧升高,导致流场中的粒子电离分布受激波位置的影响,呈现出随着壁面温度升高粒子电离程度增加的趋势。轴线压力与激波脱体距离相关,随壁面温度的升高呈现出增加的趋势。研究结果为高超声速飞行器气动热防护与气动热预测的模型构建提供理论依据。

     

    Abstract: Hypersonic vehicle travels at high speeds and in thin gas environment with high temperatures and heat fluxes. To accurately predict the flow field, the nonequilibrium Navier-Stokes equation was employed to account for the nonequilibrium thermochemical reactions. The characteristics of the flow field, including shock standoff distance, heat flux distribution, particle number distribution, and aerodynamic forces were analyzed by varying the wall temperature. The findings demonstrate that a low-temperature wall (Tw/Ti=4) fails to sufficiently expand the gas within the shock boundary layer, resulting in minimal shock standoff distance. As the wall temperature increaseing, there is an expansion of gas within this boundary layer. Consequently, both temperature and pressure rise sharply within the shock layer, leading to variations in particle ionization distribution influenced by shock wave position. It is observed that as wall temperature increaseing so does particle ionization degree. Axial pressure exhibits a positive correlation with shock standoff distance and displays an increasing trend with rising wall temperature. These research outcomes provide a theoretical foundation for developing aerothermodynamic protection systems and prediction models for hypersonic vehicles.

     

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