多孔介质模型镁合金流变铸轧LBM模拟  

LBM simulation of magnesium alloy rheological cast-rolling with porous medium model

作　　者：张莹[1] 马强[1] 陈杨华[1] 倪泽联[1] 

机构地区：[1]南昌大学机电工程学院,南昌330031

出　　处：《材料科学与工艺》2014年第2期117-122,共6页Materials Science and Technology

基　　金：国家自然科学基金(51066005);江苏省研究生创新专项基金资助(YC2013-S028)

摘　　要：根据REV尺度多孔介质格子-Boltzmann方法基本理论,建立求解高固相率半固态浆料渗流过程的热流耦合数值模型.应用模型对变孔隙率Poiseuille流动及纯扩散凝固进行模拟.LBM模拟结果与有限差分模拟吻合.分析了压差作用下浆料在平板间渗流冷却与热流耦合过程.模拟结果表明浆料渗流速度随温度降低而减慢,相同时刻下凝固潜热较大的浆料渗流Re数高.利用提出的模型初步探索了AZ91D镁合金半固态流变铸轧过程的热流场分布.A thermal-fluid coupling numerical model was built to analyze the process of high solid fraction semi-solid slurry seepage according to the lattice-Boltzmann method of REV scale porous medium. The model was applied to simulate the Poiseuille flow with various porosity and the pure diffusion solidification. The simulation results of LBM is consistent with the simulation of finite difference, and it′s correctness has been verified. The seepage cooling and the thermal-fluid coupling process of slurry between the flat was analyzed under differential pressure. The simulation results show that the slurry flow velocity decreases as temperature decreases. The RE number of slurry seepage gets higher as the solidification latent heat is raising at the same time. The proposed model has been utilized to tentatively explore the heat-flow field distribution in the process of AZ91D magnesium alloy semi-solid casting and rolling.

关 键 词：多孔介质 半固态 热流耦合 

分 类 号：O359[理学—流体力学]