Exploring on a three-fluid Eulerian-Eulerian-Eulerian approach for the prediction of liquid jet atomization

摘要

Predicting the atomization of a liquid jet in its applications, such as in fuel combustion and nuclear safety systems and in many other critical industrial applications, remains a challenging task. Using a low-computer consumption coarse-grid, this work presents a 3-D numerical method with three phases, which respectively represent the gas, continuous liquid and dispersed liquid. A Eulerian description is used for each of these phases. In addition, an algebraic interfacial area density (AIAD) model is used to consider the continuous liquid and gas phases. Meanwhile, a discrete population balance model is applied in order to take the droplet breakup and coalescences into account. The present Eulerian approach is then tested for the different liquid jets used in atomization regimes and then this is validated against the experimental data. The comparison reveals reasonable agreement in aspects such as jet spreading, droplet coalescence and the distribution of droplet sizes. Based on the simulation, the disintegration rates are found to increase from 175 kg/m3/s for case 1 to 310 kg/m3/s for case 2, which is due to increases in ejection velocity and turbulence intensity. In both the simulation and the experiment, larger-sized droplets form as the jet evolves downstream. This indicates that the coalescence between droplets overwhelms the possible breakup, meaning therefore that the diameter of the droplets increases streamwise, as shown in the comparison between D10 and D32 at the axial positions of 200 mm and 400 mm.