Numerical modelling of methanol liquid pool fires

The focus of this paper is on numerical modelling of methanal liquid pool f ires. A mathematical model is first developed to describe the evaporation a nd burning of a two-dimensional or axisymmetric pool containing pure liquid methanol. Then, the complete set of unsteady, compressible Navier-Stokes e quations for reactive hows are solved in the gas phase to describe the conv ection of the fuel gases away from the pool surface, diffusion of the gases into the surrounding air and the oxidation of the fuel into product specie s. Heat transfer into the liquid pool and the metal container through condu ction, convection and radiation are modelled by solving a modified form of the energy equation. Clausius-Clapeyron relationships are invoked to model the evaporation rate of a two-dimensional pool of pure liquid methanol. The governing equations along with appropriate boundary and interface conditio ns are solved using the flux corrected transport algorithm. Numerical resul ts exhibit a dame structure that compares well with experimental observatio ns. Temperature: profiles and burning rates were found to compare favourabl y with experimental data from single- and three-compartment laboratory burn ers. The model predicts a puffing frequency of approximately 12 Hz for a 1 cm diameter methanol pool in the absence of any air co-flow. It is also obs erved that increasing the air co-flow velocity helps in stabilizing the dif fusion flame, by pushing the vortical structures away from the flame region .