对流作用下二元合金枝晶生长的相场法模拟

Phase Field Simulation of Dendritic Growth in Binary Alloy Under Convection Effect

在二元合金相场模型研究的基础上,建立了耦合溶质场和流场的相场模型。采用有限差分法对相场模型进行数值求解,模拟了流场作用下Al-4.5wt%Cu合金凝固过程中的枝晶演化。质量和动量守恒方程采用Simple算法进行求解,解决了因压力带来的求解难题。通过数值模拟研究了强迫对流流速对枝晶生长形貌和溶质场分布情况的影响,并分析了对流速度对上游、下游和法向枝晶主干尖端生长速率和曲率半径的影响。

Based on the binary phase-field model,the phase-field model coupling with solute field and flow field was developed.An explicit finite difference numerical method was used to solve the phase-field model equations.The dendrite growth processes during the solidification of Al-4.5wt%Cu alloy under convection was simulated.At the same time,the mass and momentum conservation equation is solved by simple algorithm,the difficult calculation problem with the pressure is solved.The effects of the forced convection velocity on the distribution of solute field and the morphology of dendrite growth were investigated,and the effects of convection velocity on curvature radius and growth rate of upstream,downstream and normal to the flow were analyzed.