磁场、流体特性及几何参数对液态金属双扩散对流的影响  

Effects of magnetic field,fluid properties,and geometric parameters on double-diffusive convection of liquid metals

作　　者：尹超男 郑来运[2] 张超男 李许龙 赵秉新 Yin Chao-Nan;Zheng Lai-Yun;Zhang Chao-Nan;Li Xu-Long;Zhao Bing-Xin(School of Mathematics and Statistics,Ningxia University,Yinchuan 750021,China;School of Mechanical Engineering,Ningxia University,Yinchuan 750021,China;Ningxia Key Laboratory of Interdisciplinary Mechanics and Scientific Computing,Yinchuan 750021,China)

机构地区：[1]宁夏大学数学统计学院,银川750021 [2]宁夏大学机械工程学院,银川750021 [3]宁夏力学交叉与科学计算重点实验室,银川750021

出　　处：《物理学报》2024年第11期178-188,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12272196);宁夏自然科学基金(批准号:2022AAC03011,2022AAC03074);宁夏大学生创新创业项目(批准号:G202210749011);宁夏大学研究生创新项目(批准号:CXXM2023-09)资助的课题。

摘　　要：磁场作用下导电流体热对流是当前研究的热点问题,本文采用高精度高分辨率的数值方法对二维腔体内液态金属双扩散对流进行直接数值模拟,研究了在水平或垂直磁场作用下,磁场强度、Prandtl数、Lewis数以及高宽比对流动和传热传质的影响.研究结果表明:磁场主要表现为对流动和传热传质的抑制作用.在相同强度下,水平磁场比垂直磁场的抑制作用更大,但在较弱磁场和较强磁场时,二者对传热传质的影响效果相近.对于不同方向和强度的磁场,传热传质效率总是随着Prandtl数的增大而增大,并且在Pr=0.9附近存在解的分岔现象.随着Lewis数的增大,流动从定常流动过渡到周期流动,且传质效率受到的影响更大.在所考虑的高宽比范围内,随着高宽比的增大,无磁场及弱磁场时传热传质效率振荡变化,而强磁场下传热传质效率受高宽比的影响较小.对相同涡卷数量的流动,高宽比越小,传热传质越强.Thermal convection in conducting fluids under the influence of a magnetic field is a hot research topic.In this study,a high-precision and high-resolution numerical method is used to directly simulate the double-diffusive convection of liquid metal in a two-dimensional cavity.The study covers the effects of magnetic field strength(Ha),Prandtl number(Pr),Lewis number(Le),and aspect ratio on the dynamics of flow and heat/mass transfer under both horizontal magnetic field and vertical magnetic field.The study considers magnetic field intensities ranging from 0 to 100,Prandtl numbers from 0.01 to 1,Lewis numbers varying from 1 to 100,and aspect ratios spanning from 1 to 12.Within these specified parameter ranges,the outcomes under conditions of no magnetic field(Ha=0),weak magnetic field(Ha=10),and strong magnetic field(Ha=50)are compared with each other.The results show that the magnetic field primarily suppresses flow,heat transfer,and mass transfer.Under the same strength of the magnetic field,the horizontal magnetic field has a greater suppressing effect than the vertical magnetic field.However,the cases of weak magnetic field and strong magnetic field,their effects on heat and mass transfer are similar.Regardless of the orientation and strength of the magnetic field,the heat transfer efficiency and mass transfer efficiency always increase with Prandtl number increasing.The application of a magnetic field can reduce the increase in heat and mass transfer,and when the magnetic field strength reaches a certain level,the Lorentz force predominates,making the influence of the Prandtl number on heat and mass transfer very small.In the presence of a magnetic field,a bifurcation phenomenon is observed around Pr=0.9.Additionally,as the Lewis number increases,the flow transforms from steady flow to periodic flow,and the influence on mass transfer efficiency becomes more significant.For example,under a horizontal magnetic field,the mass transfer efficiency at the maximum Lewis number is about six times that at the minimum

关 键 词：双扩散对流 高精度 磁流体 直接数值模拟 

分 类 号：TQ0[化学工程]