(1. 江西理工大学机电工程学院，赣州 341000；
2. 江西理工大学材料科学与工程学院，赣州 341000)
摘 要: 为探明铝合金熔体在电磁场作用下的流动特征，利用Fluent软件模拟电磁场作用下铝熔体中微粒的流动轨迹，计算这些流动轨迹的混沌特征参数：最大Lyapunov指数及Kolmogorov熵。并根据不同电磁频率搅拌下铝合金熔体中微粒的运动轨迹，对其进行混沌特征判断及分析。结果表明：铝合金熔体在电磁场作用下的流动具有混沌特征；电磁频率为5、15和30 Hz时，在铝合金熔体中都发生了混沌对流，其最大Lyapunov指数都大于0，且其Kolmogorov熵随着电磁频率增大而迅速增加，说明其系统内混沌程度越大，信息损失量也越大。
关键字: 铝合金熔体；Lyapunov指数；Kolmogorov熵；混沌对流；电磁场
（1. School of Mechanical and Electronic Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. School of Materials Science and Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China）
Abstract:In order to find out the flow features of Al alloy melt under the electromagnetic field，the trajectories of the particle in Al alloy melt was simulated by the computational fluid dynamics software Fluent, and the chaotic characteristic parameters such as max Lyapunov exponent and Kolmogorov entropy were calculated, and they were used to characterize the trajectories of three groups. The chaotic characters on the flow trajectories of Al alloy melt were judged and analyzed according to the trajectories of the particle in the melt under the electromagnetic field. The results show that there is chaotic character for flow in Al alloy melt under electromagnetic field. Chaotic advection happens in the melt at different frequencies such as 5, 15 and 30 Hz. The maximum Lyapunov exponents are beyond 0. And Kolmogorov entropy increases rapidly with increasing the frequencies, indicating that its system has more degree of chaos and more information loss.
Key words: Al alloy melt; Lyapunov exponent; Kolmogorov entropy; chaotic advection; electromagnetic field
