The effect of central air flow on inverse diffusion flame height in atmospheric environment

An experimental investigation was performed to study the effect of the central air flow on the turbulent inverse diffusion flame height. The study conducted a series of experiments using two coaxial burners with different nozzle sizes in the atmospheric environment. The experimental results show that the central air flow influences the mixing process between the air/fuel jets and the flame morphology. The inverse diffusion flame height decreased with the increase in air flow rate under the same heat release rate due to the strengthening of air/fuel mixing. The flame height decreases sharply when the air flow is turbulence flow. The air–fuel momentum ratio was found to estimate the inverse diffusion flame height. The momentum flux and buoyancy flux of inverse diffusion flame have been analyzed. Considering the combinational effect of momentum flux and buoyancy flux on the inverse diffusion flame, a new correlation between the inverse diffusion flame height, air flow rate, and heat release rate has been established which provides a valuable resource for designing the inverse diffusion flame burners.