自然对流条件下柱状晶/等轴晶转变过程模拟

Simulation of columnar to equiaxed transition under natural convection condition

建立了耦合流场、浓度场、温度场的CA-LBM模型,采用该模型再现了合金在自然对流条件下柱状晶向等轴晶的转变过程,并与无对流条件下的凝固组织作对比,研究了自然对流对温度场和CET转变的影响。结果表明:自然对流促进了热的输运,加速了凝固进程,使柱状晶向等轴晶的转变提前,有细化晶粒的作用。

Lattice Boltzmann（ LB）-cellular automaton（ CA） model coupling flow field,concentration field and temperature field was established and used to simulate the columnar-to-equiaxed transition（ CET） during the process of metal ingot solidification under natural convection. Effect of fluid flow on temperature field and CET position was studied. The results show that the melt convection make the CET position ahead and help to refine the equiaxed grains. Also the convection also accelerate the heat transfer.