Title: Numerical Analysis of Pure and Blended Fuel Sonic Jets in a Mach 2 Crossflow Show Chinese title

Title: 纯燃料和混合燃料超音速喷流在马赫2横流中的数值分析

Abstract: The injection of transverse jets into supersonic compressible crossflows represents a fundamental configuration relevant to a spectrum of high-speed applications. The intricate interactions arising between the crossflow and the injected jet induce complex flow phenomena, including shock waves and vortical structures, the characteristics of which are significantly contingent upon the thermophysical properties of the injected fuel. While prior investigations have addressed the influence of various fuels, a knowledge gap persists concerning the behaviour of alternative and synthetic multicomponent fuels within this flow regime. The present work employs high-fidelity large-eddy simulations (LES) to examine the impact of ten distinct fuels-hydrogen, methane, ethylene, ammonia, syngas mixture, and a synthetic blend, alongside several NH3/H2/N2 mixtures-on the macroscopic flow structures and mixing attributes within a transverse sonic jet immersed in a Mach 2 crossflow. By maintaining a uniform momentum flux ratio across the investigated cases, the study aims to isolate the influence of the unique thermophysical properties of each fuel on the windward mixing layer, a region critically important for initial entrainment processes. The investigation quantifies the effects of molecular weight, heat capacity ratio, and density on the development and evolution of coherent structures through a detailed examination of instantaneous flow fields, vortex dynamics, scalar distributions, and turbulence statistics. The results are expected to provide pertinent insights into fuel-dependent mixing mechanisms in supersonic flows, thereby contributing to the advancement of more efficient and versatile propulsion systems. Show Chinese abstract

Abstract: 横向射流注入超音速可压缩横流代表了一系列高速应用中的基本构型。横流与注入射流之间复杂的相互作用引发了包括冲击波和旋涡结构在内的复杂流动现象，这些现象的特征显著依赖于注入燃料的热物理性质。尽管先前的研究已经探讨了各种燃料的影响，但在这一流动状态下关于替代和合成多组分燃料的行为仍存在知识空白。目前的工作采用高保真大涡模拟（LES）来研究十种不同燃料——氢气、甲烷、乙烯、氨气、合成气混合物以及一种合成混合物，连同几种NH3/H2/N2混合物——对横向声速射流中宏观流动结构和混合属性的影响，该射流浸没在马赫数为2的横流中。通过在整个研究案例中保持动量通量比的一致性，本研究旨在隔离每种燃料独特的热物理性质对风向混合层的影响，该区域对于初始掺混过程至关重要。研究通过详细检查瞬时流动场、旋涡动力学、标量分布和湍流统计，量化了分子量、热容比和密度对相干结构的发展和演化的影响。预计这些结果将为超音速流动中燃料依赖性的混合机制提供相关见解，从而有助于推进更高效和多功能的推进系统的发展。