Experimental Study Of Flame Heat Transfer In A Vertical Turbulent Wall Fire

This paper presents experimental measurements in a vertical turbulent wall fire, with a primary goal of developing a deep understating and database for heat transfer on solid surfaces where fuel pyrolyzes. An enhanced porous-plate vertical wall-fire burner was developed, and experiments were conducted with various mass transfer rates of ethylene to measure flame temperature, radiative power, spectral emission, radiative and convective heat flux. The maximum mean flame temperature is found to decrease with height, and the temperature profile in the outer flame boundary layer to be self-similar. The radiant power and heat flux show a linear increase vertically in the pyrolysis region and the peak shifts to higher evaluation with a greater fuel flow rate. Soot emission contributes a dominant fraction to thermal radiation. On the other hand, the convective heat flux promptly reduces from the flame leading edge in the laminar region at the bottom of the wall-burner and remains relatively steady in the downstream turbulent region. Convective heat flux dominates the heat transfer in the lower height while radiative heat transfer is more prominent in the upper region of the wall.(c) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.