Multidimensional numerical simulations are performed to investigate the evolution and formation of unburned fuels for a shock–fuel jet interaction scenario. A full set of Navier–Stokes equations with detailed chemical mechanisms are solved, and the results are analyzed through the Lagrangian method with the goal of improving combustion efficiency in supersonic flows. The flame morphology of a two-dimensional (2-D) non-premixed reactive shock–bubble interaction is first simulated and studied, in which unburned hydrogen is found to prevent efficient combustion. By applying the Lagrangian particle tracking method, most of the unburned hydrogen wrapped into the primary vortex turns out to be initially located upon the symmetry line of the bubble. Motivated by the idea of breaking the primary vortex, this study designs a novel geometry of a concentric bubble, which improves combustion efficiency to 94.4% in contrast to a solid fuel bubble (74%) due to multivortex interaction and a thick bridge structure. With the consistency between qualitative and quantitative 2-D and three-dimensional (3-D) flow dynamics, the idea of a 2-D concentric-bubble configuration is effectively extended to a 3-D coaxial jet interacting with oblique shock despite the existence of Kelvin–Helmholtz instability.

执行多维数值模拟以研究冲击-燃料射流相互作用场景中未燃烧燃料的演变和形成。求解具有详细化学机理的全套 Navier-Stokes 方程，并通过拉格朗日方法分析结果，以提高超音速流动中的燃烧效率。首先模拟和研究了二维 (2-D) 非预混反应冲击-气泡相互作用的火焰形态，其中发现未燃烧的氢气会阻止有效燃烧。通过应用拉格朗日粒子追踪方法，大部分包裹在初级涡旋中的未燃烧氢最初位于气泡的对称线上。受到打破初级漩涡的想法的启发，这项研究设计了一种新颖的同心气泡几何形状，由于多涡流相互作用和厚桥结构，与固体燃料气泡 (74%) 相比，燃烧效率提高了 94.4%。由于定性和定量 2-D 和三维 (3-D) 流动动力学之间的一致性，2-D 同心气泡配置的想法有效地扩展到 3-D 同轴射流与斜激波相互作用，尽管存在开尔文-亥姆霍兹不稳定性。