Experimental study on the lip height effect on combustion and flow characteristics of n-heptane pool fire
In this study,an experimental investigation was conducted to examine the combustion and flow characteristics of n-heptane pool fires,specifically focusing on the influence of lip height on flame morphology,velocity distribution,and pulsation behavior.The results demonstrate that increasing the lip height leads to a decrease in flame height and an initial increase followed by a decrease in flame width due to Rayleigh-Taylor instability effects.Moreover,lip height significantly enhances flow instability,alters the entrained airflow pattern into the fuel pan,and promotes vortex generation at the base of the flame.As for axial height variations,there is a gradual transition from irregular to self-similar flame velocity distribution attributed to the pronounced sinking of the bottom region,affecting axial velocity distribution in near-field regions.Additionally,two mechanisms contribute to flame pulsation induced by lip height;one mechanism promotes airflow disturbance and exacerbates flame instability,while another restricts air inflow pathways,potentially weakening overall flame dynamics.The competition between these mechanisms results in a non-monotonic variation of pulsation frequency as lip height increases.
Lip heightFlame heightVelocity distributionPulsation frequency
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