A double-k–ε and multi-δ pdf model for turbulent gas–liquid reacting flows

The gas–liquid reacting two-phase flow of a gaseous SF6 jet submerged in liquid metal Li is numerically simulated by a two-fluid model. To describe the changes of the flow pattern in the two-phase flow, a double-k–ε two-phase turbulence model is developed and adopted. A multi-δ-pdf model is proposed and applied to simulate the turbulent combustion of gaseous SF6 with liquid metal Li. The gas and liquid velocities, void fraction, shape of the penetrating region (the region containing the gas phase) and the mixture fraction related to gas temperature and species concentration are predicted. Comparison with the results using a single-fluid model shows that current predictions are reasonable in reflecting the influence of velocity slip between the two phases and capable of predicting Li/SF6 submerged combustion.