COMPUTATION OF TURBULENT EVAPORATING SPRAYS WITH WELL-SPECIFIED MEASUREMENTS - A SENSITIVITY STUDY ON DROPLET PROPERTIES

An extensive numerical study was carried out for a confined evaporatin g spray in a turbulent, heated gas flow using a published well-defined experimental dataset. The Eulerian-Lagrangian stochastic models were employed for spray calculations wherein the gas turbulence was modeled using the second-moment transport model for the Reynolds stresses and heal-fur vectors, and the droplet dispersion was modeled using the La grangian stochastic models with or without temporal correlations. Two fashions of the infinite-conduction-evaporation model were studied, bo th of which have taken into account the variable gas-film properties b y the 1/3-rule. Numerical results for the droplet phase, i.e., the mea n diameters, mass fluxes, mean and fluctuating velocities were present ed and discussed by comparison with the experimental data. The sensiti vity of various droplet properties to the number of droplet trajectori es at the inlet, the drift correction approaches for the improvement o f mass-flux predictions, and the evaporation models was investigated i n terms of the well-defined experimental dataset. Results show that th e droplet mean velocities are generally not sensitive to all the facto rs considered, that droplet r.m.s. velocities downstream are sensitive to the number of trajectories, that the droplet mass-flux accumulatio n near the centreline can be substantially improved by using a new dri ft correction approach, and that mass-flux predictions are sensitive t o the evaporation models.