NUMERICAL STUDY OF THE EFFECTS OF GAS TEMPERATURE-FLUCTUATION ON A TURBULENT EVAPORATING SPRAY

Computational study of a turbulent evaporating spray was conducted usi ng a Eulerian-Lagrangian hybrid model. Eulerian computation of the tur bulent gas phase consists of the second-moment closure for the momentu m equations and the heat-flux transport closure for the energy equatio n. Lagrangian computation of the droplet phase consists of an anisotro pic droplet dispersion model for the motion of droplets in turbulent g as flow. Complete initial conditions from experimental measurements we re used to investigate the effects of gas temperature fluctuation on d roplet evaporation. Numerical results for the droplet phase obtained b y including and excluding gas temperature fluctuation in the droplet L agrangian equations were compared with each other, together with the e xperimental measurements. It was found that the inclusion of the gas t emperature fluctuation has a strong effect on the vaporization of indi vidual droplets, but has a negligible effect on global spray propertie s of ensemble-averaged droplet properties such as the velocity, diamet er, and mass flux.