Kai Xie, Na Xiao, Caixia Li, Zhenjiang Zhang, Jinxi Zhou, Gan Cui, Shusen Wang, Yunjing Cui, Jianxin Wang
To address the flame geometry mismatch in applications such as high-altitude diesel burners, this study proposes a horizontal dual-nozzle jet configuration. The flame characteristics were experimentally investigated by systematically varying two key operational parameters: the global equivalence ratio and the fuel flow distribution between nozzles. A probability-based image processing method was employed to analyze flame evolution. The results quantitatively reveal the variation laws of dimensionless flame projection length, height, and uplift slope. Notably, the trends in flame fluctuation dimensions with global equivalence ratio are significantly affected by the auxiliary nozzle flow rate, with a distinct shift observed over an equivalence ratio interval as narrow as 0.15. Furthermore, based on Richardson number and Reynolds number, the flame regime is classified into a buoyancy-driven region, a chemistry-dominated region, and a strong turbulence dominates region. A comparison of dimensionless fluctuation parameters demonstrates that the vertical fluctuation parameter γ is a more suitable indicator for assessing flame stability than the horizontal parameter β . Finally, the study elucidates how the flame trajectory can be actively regulated by the secondary nozzle flow rate and the global equivalence ratio, identifying the parameter ranges over which trajectories converge. These findings provide fundamental data and theoretical support for achieving precise control of flame shape and stability in dual-nozzle burner systems.