The Effect of Thin Fuel Bed Modelling on CFD Simulation and Analytical Analysis of Compartment Fire Study

In this study, the geometrical details of low elevated fuel beds are examined in a compartment fire numerically and analytically, and the results are compared with experimental data. Moreover, the effect of the complexities of fuel bed geometry on analytical and simulation parameters is analysed by various fuel bed designs. One of the major parameters that affect thermal distribution in a compartment is fuel bed height (or fuel free surface height) to opening height ratio. Results show that even the negligible amounts of this parameter can significantly affect field parameters like velocity and temperature. However, overall parameters like upper layer temperature do not vary significantly. The angle of the thermal plume is found to vary between almost zero degrees in the exact implementation case to nearly 90 degrees where the height ratio is zero. Energy analysis of the compartment shows that although the fuel is completely burnt in all cases, the radiative and convective heat loss through the walls and the heat loss through the door may vary up to 13, 12, and 15.5 per cent, respectively. As a result of comparing numerical results with analytical correlations for upper layer temperature (MQH correlation) and opening mass flow rates (Rockett correlation), the results indicate that thin fuel bed elevation has a negligible effect on the mentioned parameters, and both correlations can be used to predict their behaviour accordingly.