Experimental Study on Flame Height and Oscillation Behavior of Linear-source Buoyant Turbulent Diffusion Jet Flame Under Sub-atmospheric Pressures

In this paper, experiments of linear buoyant turbulent propane jet fire at various sub-atmospheric pressures were carried out, and different aspect ratios of burners were considered. The evolutions of flame height and flame oscillation frequency with the burner aspect ratio, ambient pressure and heat release rate are studied. The experimental results show that the flame height decreases with the increase of burner aspect ratio or pressure, and it increases with the increase of heat release rate. However, the flame oscillation frequency decreases with the increase of burner aspect ratio and increases with the increase of pressure, and heat release rate has no significant effect on the flame oscillation frequency. Based on the analysis of air entrainment mechanism and the dimensionless relationship between Strouhal number (St) and Froude number (Fr), non-dimensional models of flame height and flame oscillation frequency of linear source jet flames coupled with the ambient pressure effect are established. © 2024 Science Press. All rights reserved.