Radiation Affected Liquid Fuel Burning on Water

Abstract

A model for the radiation affected liquid fuel burning on water is developed which improves substantially on an existing model by including the turbulent fire plume and the explicit effects (hotness and optical thickness) of fire radiation. In achieving these objectives, the experimental literature on flame height and velocity is utilized. The fire plume above the slick is divided into three regions: the continuous flame; the intermittent flame; and the thermal plume. To describe the fire plume, Taylor's entrainment model is used which assumes top-hat profiles for the radial velocity and temperature and relates the entrainment and vertical velocities at a given height. The contributions from gaseous combustion products, mainly CO₂ and H₂O, as well as from particulate matter to radiative heat transfer are also accounted for. Both linear and nonlinear solutions are obtained and compared to examine the accuracy of the usual approach of linearization in the radiative transport equations. The effect of radiation on fuel burning is demonstrated as a function of the flame hotness and optical thickness. Radiation is shown to lower the temperatures in the high temperature region of the flame and raise the temperatures in the low temperature region near the fuel surface. It is further shown that fuel burning increases monotonically with increase in radiation effects. It is concluded that the contribution of fire radiation to fuel burning is substantial and may exceed that of conduction heat transfer by an order of magnitude. The model is also compared with available data for crude oil burning on water, yielding reasonable trends within the uncertainty of the experimental literature.