Influence of swirl number and air preheating on turbulent mixing in hydrogen–methane blends within a swirl-stabilized burner
Amin Bekhradinasab, Shidvash Vakilipour, Jafar Al-Zaili
Abstract
This study investigates the effects of swirl number and air preheating on the turbulent mixing characteristics of pure methane and hydrogen–methane fuel blends in a swirl-stabilized burner. Utilizing large eddy simulations (LES) with the Wall-Adapting Local Eddy-viscosity (WALE) sub-grid model, the turbulent flow fields are calculated and validated using non-reactive cases with varying swirl numbers. The research explores the combined impact of varying swirl numbers, preheating intake air, and hydrogen addition on flow structures and mixing behavior. This integrated approach clarifies how these factors influence flow field structures, stoichiometric volume and length, intensity of segregation, scalar dissipation rate, variance spectral density, and probability density function of mixture fraction. These insights can enhance the efficiency and cleanliness of hydrogen–methane combustion technologies. The findings offer a guidance for optimizing hydrogen–methane fuel blends, contributing to the transition towards sustainable energy sources. • Numerically assessed the impact of hydrogen-methane blending on mixing characteristics. • Explored swirl number’s impact on flow dynamics and mixing quality. • Demonstrated the effect of air preheating on fuel distribution patterns. • Investigated turbulence, scalar dissipation, and segregation due to hydrogen addition. • Explored hydrogen blending, swirl, and preheating effects on stoichiometry.