An Experimental Study of Radiative Properties of Pool Fires Of an Intermediate Scale

Abstract The radiative heat flux to the fuel surface in heptane pool fires on circular pans of 0.3-1.0 m diameter was measured experimentally by use of combinations of Garden-type fluxmeters with receiving surfaces of different emissivity as functions of rad ial position and of pan size. In the initial transient stage of the fire evolution, the internal radiat ive flux showed an overshoot followed by a considerable fall in larger pool fires. In the steady burning stage,the ratio of the internal flux to the external flux showed a trend to become smaller with the increase Of pan size. The two above mentioned features imply the importance of a certain kind of radiation blockage in larger fires. Simple two-layer models were employed in order to explain the observed features qualitatively.