流向磁场作用下二维磁流体槽道湍流直接模拟  

DNS of two-dimensional MHD turbulent channel flow under action of streamwise magnetic field

作　　者：陈智[1] 张劲柏[1] 李椿萱[1] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191

出　　处：《北京航空航天大学学报》2011年第5期605-609,共5页Journal of Beijing University of Aeronautics and Astronautics

摘　　要：对低磁雷诺数近似下流向磁场作用的二维磁流体槽道湍流进行了直接数值模拟(DNS,Direct Numerical Simulation),给出了Re=10000时不同磁相互作用数下二维磁流体槽道湍流的近壁速度分布、湍流脉动速度均方根、雷诺应力等统计量的变化,并与中性流体二维槽道湍流进行了比较.结果表明:流向磁场作用会导致对数区上移;雷诺应力最大值随磁相互作用数呈线性变化;随着磁相互作用数的增大,下壁面平均涡量的时间演化由拟周期性向周期性转变,且脉动周期逐渐增大并当流动层流化后下壁面平均涡量成为常值.A direct numerical simulation（DNS） of two dimensional,conducting turbulent channel flow under the action of applied streamwise magnetic fields was performed based on the low magnetic Reynolds number approximation.The numerical results with Re=10 000 under the action of different magnetic interaction numbers ranging from 0.001 to 10 were analyzed.The computed variations of the near-wall velocity distribution,root mean squares（RMS） of the fluctuation velocity,and the Reynolds stresses were presented and compared to the case with neutral fluid.The results show that streamwise magnetic field results in an upward shift of the log layer,the maximum of Reynolds stress varies linearly with interaction number.With the increment of interaction number,the time evolution of average vorticity of the bottom wall shows a growing trend in periodicity and the average vorticity of the bottom wall becomes a constant value finally when relaminarization happens.

关 键 词：磁流体力学 湍流 槽道流动 直接数值模拟 

分 类 号：O361.5[理学—流体力学]