NUMERICAL SIMULATION OF FLOW AROUND A HOT PARTICLE WITH A VAPOR FILM USING A VOLUME-OF-FLUID INTERFACE TRACKING METHOD

摘要

Movement characteristics of a melt particle with a vapor film moving in coolant could affect the distribution of phases and then the global behavior in premixing phase of steam explosion. Detail CFD simulation of flow around the particle could improve the understanding of the resistance on the particle. The work of this paper is to establish a CFD code to simulate the vapor film flow field for this purpose. The result of pressure and velocity distribution around hot particle could be used to calculate the total force exerted on the particle and then predict its movement characteristics.rnIn order to treat with the water-vapor free surface and rapid vaporization on it, an interface tracking method based on Volume-of-Fluid (VOF) with Piecewise-Linear Interface Construction (PLIC) is proposed. Some special treatment is taken to deal with the discontinuous velocity field due to rapid phase change. Because the interface is reconstructed during the solution, radiation heat transfer which is dominant in the whole process could be taken into account more easily. Continuum Surface Force (CSF) model is used for surface tension.rnPreliminary simulation results have been obtained. The results will be compared to experimental data later.