Achieving stable and efficient combustion in high speed conditions presents significant challenges due to the coupled effects of turbulent mixing, finite-rate chemistry, and short residence times. Prior studies have demonstrated the critical interplay between fuel-air mixing and chemical kinetics, where incomplete mixing limits combustion efficiency. However, the role of turbulence-chemistry interactions under premixed conditions, particularly their influence on the reaction zone structure and its modification by turbulence, remains underexplored. This study investigates these interactions by employing a fully premixed fuel-air mixture, which isolates chemical timescales from air-fuel mixing, to examine turbulence-chemistry-compressibility interaction in a confined high speed flow. Simulations utilize adaptive mesh refinement (AMR) with multi-step chemical kinetics to capture the finer details of critical flow features such as flame fronts and shocks while maintaining computational efficiency. The computational setup consists of a constant-area duct with a rectangular cavity. Key findings highlight significant flame wrinkling and the emergence of complex three-dimensional flow structures. Vorticity generation is primarily driven by shear-induced stretching and tilting effects. Chemical reactions and associated heat release induce oblique shock waves, which contribute to flame stabilization. Initial flame growth aligns with boundary layer thickness development, whereas flame dynamics near the cavity is strongly influenced by the influence of oblique shock waves. • Adaptive Mesh Refinement (AMR) with embedded boundary (EB) method and multi-step chemical kinetics are utilized to simulate supersonic reacting flow in a confined geometry. • A premixed air-fuel mixture is used to isolaote the effect of chemical kinetics and heat addition under supersonic conditions from air-fuel mixing. • Significant flame wrinkling and complex three-dimensional flow structures are observed. Initial flame growth aligns with boundary layer development, while flame dynamics near the cavity are influenced by oblique shock waves, aiding flame stabilization.
Singh et al. (Sun,) studied this question.