磁场对磁性湿颗粒运动机理的影响

为了了解磁流化床内磁性湿颗粒的运动特性,数值模拟了匀强磁场作用下磁性湿颗粒的运动。数学模型上,采用离散元法(DEM)模拟颗粒运动,同时考虑磁场和液桥的双作用力模型。仅针对二维溃坝问题进行数值模拟,分别研究磁场和液桥对颗粒行为的影响。数值模拟结果发现:无磁场作用时,液体体积分数增加,颗粒运动剧烈程度相对减弱,颗粒聚集行为增强;有磁场作用时,颗粒形成平行于磁感线方向的链,显著降低了颗粒的平均速度和平均位移。

Influence of magnetic field on movement mechanism of wet magnetic particles

To understand the movement behavior of wet magnetic particles in magnetic fluidized beds, the numerical simulations of wet magnetic particles movement under effect of uniform magnetic field are performed. In the mathematical model, the discrete element method (DEM) is adopted to simulate the particles movement, while both magnetic force and liquid bridge force models are considered. A two-dimensional dam-break problem is simulated to observe the effects of magnet-field and liquid bridge on the behavior of particles motion.Theresults show that:without magnet-field, as liquid-volume friction increasing, the speeds of particles become slowly and the particles are gathered obviously. When a magnet-field is applied, the particles form some chains parallel to the direction of magnetic sense, which reduce the average velocity and displacement of particles.