Experimental Study of Sidewall and Pressure Effect on Vertical Downward Flame Spread Over Insulation Material

Abstract

In this work, experiments were conducted to investigate the sidewall and pressure effect on vertical downward flame spread over insulation material. Experimental results and theoretical analysis are presented to reveal the mechanisms. Results showed that the flame spread rate and mass loss rate increased, while deceleration trends were observed with the increase in sidewall geometrical factor. The maximum increase for flame spread rate and mass loss rate without and with sidewalls was approximately 20 % and 40 %, respectively. Flame spread rate, flame height, and mass loss rate were in positive relationships with pressure. By providing an air entrainment analysis, it is found that, theoretically, flame spread rate is proportional to induced flow speed which increases with geometrical factor and mass loss rate and decreases with back wall width. The theoretical analysis is in good agreement with experimental results.