Experimental Study on Radiation Blockage of Small-Scale Vertical PMMA Fires

Abstract

In this work, experiments were conducted to evaluate the effect of exterior radiation on vertical PMMA fires. The mass loss, flame height, and radiant heat flux were measured. A critical heat flux of 10 kW/m2 was determined as a boundary for radiation blockage effect. For lower exterior radiation heat fluxes (<10 kW/m2), the mass loss rate of the sample increased slowly, while it increased rapidly for higher exterior radiation. The critical heat flux of 10 kW/m2 was also reflected in the flame height data. The total radiation heat feedback to the sample surface had a nearly linear dependence on the external heat radiation for higher exterior radiation. The total radiation blockage fraction decreased firstly and increased subsequently. Under same exterior radiation heat flux, vertical PMMA fires had a higher total radiation blockage than horizontal fires.