High-Fidelity Numerical Analyses for Hydrogen Jet-Flames in Crossflow

Abstract This study compares two advanced numerical approaches in the context of investigating flame stabilization in hydrogen jets in crossflow (JICF). The first approach utilizes a highly resolved large-eddy simulation (LES) coupled with a strain-based flamelet manifold combustion model. The second approach involves a high-fidelity direct numerical simulation (DNS) with detailed chemical kinetics for the same JICF case. To capture the complex flame dynamics, the LES solver uses a static, highly resolved mesh, whereas the DNS solver employs adaptive mesh refinement (AMR) based on flame thickness. Both simulations are validated against experimental data, with a specific focus on flow regimes characterized by the Reynolds number, particularly mixing effects on flame stabilization. The flame dynamics are further analyzed through hydroxyl radical mass fraction contours and spatiotemporal scatter plots of key quantities. The study reveals that turbulent mixing regions are captured well by the LES model. However, on the lee side of the flame, differential diffusion significantly affects flame stabilization, which occurs further downstream in the DNS simulations. This comparison presents a holistic perspective on the capabilities of these methods in terms of spatial and chemical basis, highlighting their potential to study the dynamics of practical combustion systems under varying conditions.