Flame height and axial plume temperature profile of bounded fires in aircraft cargo compartment with low-pressure

Abstract

A series of n-heptane buoyancy bounded fire tests (center fires, wall fires, corner fires) are conducted in a full-scale simulated aircraft cargo compartment at 70 kPa, 80 kPa, 90 kPa, 100 kPa to measure the flame heights and axial plume temperatures. Based on the Heskestad's model, the flame heights at different horizontal positions are normalized by introducing the respective mirror coefficients β of wall fires and corner fires, a prediction formula for flame heights with pressure correction coefficients Kp is established. The influence of air entrainment on flame height is further revealed by analyzing the experimental data through Quintiere and Grove's model. In addition, by comparing with the McCaffrey's model after the introduction of the mirror coefficient β, it is found that the axial temperature values of wall fires and corner fires are lower than the predicted values because the model ignores the heat radiation feeding back into the plume from the heated sidewalls, and the longitudinal dimension of the corner fire plumes is stretched resulting in an extended intermittent region. The prediction equations for the axial temperature distribution of bounded fires in low-pressure are proposed by introducing pressure correction coefficients.