Aerothermodynamic Optimization of Aerospace Plane Airfoil Leading Edge

ABSTRACT: Aiming to mitigate the aerodynamic heating during hypersonic re-entry, the aerothermodynamic optimization of aerospace plane airfoil leading edge is conducted. Lift-to-drag ratio at landing condition is taken as a constraint to ensure the landing aerodynamic performance. First, airfoil profile is parametrically described to be more advantageous during the optimization process, and the Hicks-Henne type function is improved considering its application on the airfoil leading edge. Computational Fluid Dynamics models at hypersonic as well as landing conditions are then established and discussed. Design of Experiment technique is utilized to establish the surrogate model. Afterwards, the previously mentioned surrogate model is employed in combination with the Multi-Island Genetic Algorithm to perform the optimization procedure. NACA 0012 is taken as the baseline airfoil for case study. The results show that the peak heat flux of the optimal airfoil during hypersonic flight is reduced by 7.61% at the stagnation point, while the lift-to-drag remains almost unchanged under landing condition.摘要：为缓解高超声速再入过程中的气动热问题，本研究开展了航天飞机翼型前缘的气动热力学优化设计。以着陆工况下的升阻比作为约束条件，保障着陆阶段的气动性能。首先，为提升优化过程中的建模效率与灵活性，对翼型外形进行参数化描述，并针对翼型前缘的应用场景改进了Hicks-Henne型函数。随后建立高超声速及着陆工况下的计算流体动力学（Computational Fluid Dynamics, CFD）模型并开展验证分析；采用试验设计（Design of Experiment, DOE）方法构建代理模型。在此基础上，结合上述代理模型与多岛遗传算法完成优化流程。本研究以NACA 0012翼型作为基准翼型开展案例研究，结果显示：优化后的翼型在高超声速飞行阶段的驻点热流峰值降低了7.61%，且着陆工况下的升阻比基本保持不变。