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边界层的转捩预测是高超声速飞行器气动力和热防护设计的关键问题之一。基于此,研究了壁面温度条件对采用转捩模式预测边界层转捩的影响,对k-ω-γ转捩模式的时间尺度和间歇因子生成项进行了修正。在非湍流脉动概念所模化的不稳定扰动时间尺度中,考虑了壁面温度条件对流动转捩的影响,引入壁面冷却对不稳定扰动最大增长率、临界雷诺数等量的模化。采用修正后的k-ω-γ转捩模式计算高超声速小球头锥零迎角流动转捩问题,通过与稳定性分析和原始k-ω-γ转捩模式计算结果的对比,发现改进后的模式在绝热和等温两种壁温条件下,能够较为准确地模拟第一模态和第二模态的不稳定频率、最大增长率,并能正确预测转捩位置。
Boundary-layer transition prediction is one of the key issues in the aerodynamic and thermal design of hypersonic vehicles. Based on this, the influence of the wall temperature on the prediction of the boundary layer transition by the transition pattern is studied, and the time scales and the generation of intermittent factors of k-ω-γ transition pattern are modified. In the unstable disturbance time scale modeled by the non-turbulent pulsation concept, the influence of wall temperature on the flow transition was considered, and the maximum cooling rate instability disturbance and the critical Reynolds number modeled by wall cooling were introduced. Using the modified k-ω-γ transition model to calculate the zero-angle flow transition problem of hypersonic ball-nose cone, by comparing with the stability analysis and the original k-ω-γ transition model, it is found that after the improvement Mode can simulate the unstable frequency and maximum growth rate of the first mode and the second mode more accurately under adiabatic and isothermal two kinds of wall temperature conditions and can correctly predict the position of the transition.