Large Eddy Simulations (LES) of an over-expanded conical nozzle are performed to study the complex interaction between the turbulent boundary layer, the internal shock wave and the separated mixing layer. Both wall-modeled (WM) and wall-resolved (WR) LES strategies are employed to investigate the three-dimensional unsteady aspect of shock-wave boundary-layer interaction (SWBLI). First, a comparison of flow behavior in a conical nozzle against an equivalent planar nozzle is made. It was found that whilst both configurations may share common flow features such as large-scale turbulent structures and shock-wave patterns, they show contrasts on the symmetry of the flow and the shock dynamics. In particular, the latter was found to have a shorter excursion length in conical nozzle compared to the planar one. The strong adverse pressure gradient tends to reduce the amplitude of the shock movements in conical flows. Additionally, the dynamic mode decomposition (DMD) analysis showed the existence of two unsteady modes; the non-helical modes which are low-frequency based, appearing mainly in the streamwise forces and the helical modes which are high frequency dominated modes and are largely responsible for the side side-loads generation.

进行了超膨胀圆锥形喷嘴的大涡模拟（LES），以研究湍流边界层，内部冲击波和分离的混合层之间的复杂相互作用。壁模型（WM）和壁分辨（WR）LES策略都用于研究冲击波边界层相互作用（SWBLI）的三维非稳态方面。首先，将锥形喷嘴中的流动行为与等效平面喷嘴进行了比较。已经发现，虽然两种构造可以共享共同的流动特征，例如大型湍流结构和冲击波模式，但它们在流动对称性和冲击动力学方面显示出对比。特别地，发现后者在圆锥形喷嘴中具有比平面喷嘴短的偏移长度。强烈的反压力梯度趋于减小圆锥形流动中冲击运动的幅度。此外，动态模式分解（DMD）分析表明存在两种非稳态模式。基于低频的非螺旋模式主要出现在流向力中，而作为高频控制模式的螺旋模式则主要表现在侧向载荷的产生上。