类X-51A飞行器非定常湍流精细模拟

针对类X-51A飞行器在超声速大迎角状态下存在的大范围非定常分离流动，开展了精细化湍流数值模拟研究。计算基于高阶格式下的延迟分离涡模拟方法（DDES），来流马赫数为2.5，迎角为10°。分析了该复杂流场中存在的分离流动现象、分离流动诱导的气动特性变化规律以及压力脉动特点；其中重点研究了壁面压力脉动强度分布情况和监测点压力脉动频谱特性。分析结果表明:飞行器大迎角飞行时从侧缘诱导出明显的分离涡，并对尾部舵面产生干扰；受干扰尾舵表现出明显的非线性及非定常气动特性；分离涡的存在导致飞行器尾舵前缘等位置的壁面压力脉动显著增强，200~300 Hz的低频高幅值脉动可能会导致结构破坏。 

High-resolution unsteady turbulence simulation of an X-51A-like aircraft

High-resolution turbulence simulations were performed for an X-51A-like aircraft model to investigate its complex unsteady separation flow caused by high angle of attack conditions. The calculation is based on delayed detached-eddy simulation (DDES) methodology under high order. Flow Mach number is 2.5, and the angle of attack is 10°. In this paper, separation flow phenomenon, separation flow induced aerodynamic characteristic variation law and pressure fluctuation features are analyzed. Especially, the distribution of wall pressure fluctuation and the spectrum characteristics of the monitors are mainly studied. The result shows that lateral edges of the model lead to a large number of separated vortices when the aircraft flies under large angle of attack, which cause strong interference with the vertical tail rudder. The interfered tail rudder exhibits obvious nonlinear and unsteady aerodynamic properties. In addition, the presence of separation vortices also leads to a significant increase in pressure fluctuation on the aircraft wall, especially on the leading edge of tail rudders. The power spectrum density of pressure shows that low frequency and high amplitude fluctuation of 200-300 Hz may cause structural damage.