Numerical simulation of interfacial behaviour between molten steel and slag in medium-thin slab continuous casting mold

The flow field of molten steel and the interfacial behaviour between molten steel and liquid slag in a medium-thin slab continuous casting mold with 135mm thickness were simulated by using the VOF(volume of fluid) method and Lagrangian discrete phase model,and the effects of mold width,nozzle submergence depth and port angle,casting speed,and argon gas injection on the flow and the level fluctuation of molten steel were investigated.The results show that the molten steel from the submerged entry nozzle with three ports flows into the mold and forms three re-circulation zones including one upper re-circulation zone and two lower re-circulation zones.Argon gas injection results in a secondary vortex flow in the upper zone near the nozzle.For a given casting speed,increasing the downward port angle and submergence depth of nozzle both can restrain the steel/slag interfacial fluctuation effectively.Increasing the casting speed and mold width with a given casting speed both would worsen the level fluctuation.