Simulation Of Fluid Flow Of Molten Steel In Slab Continuous Casting Mold Based On Lattice Boltzmann Method

In the continuous casting process,the flow field distribution in the mold determines the metallurgical transport behavior such as initial shell growth,mold flux melting and inclusion floating.It is of great significance for the quality control of continuous casting slab to study the flow transmission characteristics in the mold.Lattice Boltzmann Method(LBM),developed from Lattice Gas Automata(LGA),is a mesoscopic simulation method with the advantages of both macro-scale continuous model and micro-scale molecular dynamics.LBM model has the advantages of simple program,convenient boundary conditions and easy parallelism.It has been developed rapidly in the simulation of micro and mesoscopic scale flow problems.However,there are few studies on the application of LBM in the continuous casting process.This paper aims to develop a numerical method for calculating the flow behavior inside continuous casting mold based on LBM,and develop a set of numerical program to discuss the applicability and feasibility of LBM in calculating the flow behavior of molten steel in continuous casting mold.Firstly,the paper analyzed and deduced the establishment process of lattice Boltzmann equation,introduced the processing methods of common LBM models and boundary conditions,then selected the DDF-LBE model to model the flow process and develops the corresponding program.To verify the correctness of the model and program,two classical flow examples,the top-driven flow and the Poiseuille flow were simulated and compared with the existing research results.On this basis,taking the flow process in the straight-through nozzle mold as the research object,the corresponding physical model was established.Reynolds number was chosen as the similarity criterion and the actual parameters are dimensionless treated according to the similarity criterion.The flow field in the mold was simulated to obtain the flow characteristics of molten steel.In order to ensure a suitable Reynolds number for simulating the flow behavior,the characteristics of the vortex position in the flow field with different Reynolds numbers were investigated and the influences of Reynolds number on the disorder of flow field are analyzed.After that,the flow field under different casting parameters such as casting speed,nozzle immersion depth and slab section size were calculated.Based on the results,the molten steel flow characteristics of vortex center position,impact depth and velocity distribution were discussed,and the influence of different casting parameters on the flow field distribution was discussed,which provided a reference for the flow field of the mold and the optimization of casting process.