Low air pressure effects on burning characteristics of typical oil with forced irradiance

In this paper, a report is given on an experimental study of the combustion characteristics of typical oil with forced irradiance under two fixed ambient pressures, which may occurred in real fires. Mass loss and flame axial heat flux distribution were measured to evaluate the hazards. The burning intensity at reduced pressure is relatively lower under the circumstance without incident irradiance because the thin air for reduced pressure may attenuate the combustion. However, the burning intensity at lower pressure is higher due to the lower boiling temperature when the irradiance reaches to 10 kW/m².The flame could engulf sufficient air to complete the combustion process for atmospheric pressure condition compared with that under low pressure, and thus resulting in relatively higher flame temperature for a fixed flame height. While in the unified plume region, the weaker air entrainment under lower pressure leads to a poorer cooling effect, i.e. higher plume temperature.