CELLULAR AUTOMATON-LATTICE BOLTZMANN MODEL FOR THE SIMULATION OF DENDRITIC GROWTH WITH MELT CONVECTION
A two-dimensional (2D) model based on a cellular automaton coupled with the lattice Boltzmann method (CA-LBM) was developed for the simulation of dendritic growth in a flowing melt. In the present model, a cellular automaton (CA) approach is used for modeling dendritic growth. Instead of conventional continuum-based Navier-Stokes (NS) solvers, the present model adopts a kinetic-based lattice Boltzmann method (LBM) for fluid flow computations, which describes flow dynamics by the evolution of a distribution function of moving pseudo-particles. Mathematically, the LBM approach can be regarded as a cellular automaton where the state at each node has vector character (fluid droplets with momentum vector). To calculate fluid flow, solute and temperature fields simultaneously, three sets of distribution functions of the lattice Bhatnagar- Gross-Krook (LBGK) scheme are employed. The proposed CA-LBM model was validated by the comparison with the Lipton-Glicksman-Kurz (LGK) analytical model. The simulated steady state tip velocity as a function of initial solute composition of Al-Cu alloys for pure diffusive dendritic growth is very close to the predictions of the LGK model. The CA-LBM model was applied to simulate both single and multi- equiaxed dendritic growth of Al-Cu alloys in a forced flow. The typical asymmetric growth features of convective dendrite were predicted. The evolution of solid fraction for pure diffusive and convective dendritic growth simulated from the CA-LBM model coincides well with those from the previously developed CA-FDM and CA-NS models. It is also found that the CA-LBM model has significant advantages of numerical stability and computational efficiency compared to the CA-NS model.
Solidification Modeling Cellular automaton Lattice Boltzmann method Dendritic growth Diffusion Convection
Dongke SUN Mingfang ZHU Dierk Raabe Chun-Pyo HONG
School of Materials Science and Engineering, Southeast University Nanjing 211189, China Max-Planck-Instirut fur Eisenforschung Max-Planck-Strasse 1, Dusseldorf 40237, Germany Center for Computer-Aided Materials Processing (CAMP), Dept. of Metallurgical Engineering, Yonsei Un
国际会议
大连
英文
249-258
2007-08-19（万方平台首次上网日期，不代表论文的发表时间）