LBM modelling of supercooled water freezing with inclusion of the recalescence stage

Once nucleated, the solidification process of supercooled water undergoes stages of recalescence, freezing, and solid cooling. In existing LBM models for predicting the water solidification process, the recalescence stage was often treated by simply setting the system temperature to 0 °C on account of the latent heat release. However, apart from the temperature rise, another important feature of the recalescence stage is the rapid growth of dendritic ice over the entire supercooled space, which was often overlooked. In this study the recalescence stage is included in the conventional LBM, aiming to quantify the effect of initial ice fraction distribution on the freezing kinetics of supercooled water. Good agreements are achieved between the predicted results and the experimental data on the kinetics of water freezing in terms of the local temperature variation, freezing rate and evolution of the ice-water interface. However, the conventional LBM without considering the recalescence stage provides a poor description of ice-water interface evolution. The discrepancy between the predicted results using models with and without considering the recalescence stage increases as the supercooling increases and rises to 31% for a supercooling of 20 °C. Moreover, the method based on the Stefan number proves valid in calculating the initial ice fraction over the entire spectrum of supercooling degrees, whereas for high supercooling degrees (>28.2 °C) the application of the enthalpy-based method leads to erroneous results. For water systems of small volume that often bear a supercooling more than 30 °C, the recalescence stage should be considered in the modelling.