MHD Stagnation Point Flow of a Micropolar Fluid Towards a Heated Surface
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摘要: 分析了有均匀横向磁场作用时,导电微极流体垂直冲击受热面时形成的二维驻点流动问题.应用适当的相似转换,将连续、动量、角动量及热量的控制方程,及其相应的边界条件,简化为无量纲形式.然后,利用以有限差分离散化为基础的算法,求解简化了的自相似非线性方程.用Richardson外推法,进一步求精其结果.以图表形式表示磁场参数、微极性参数、Prandtl数对流动和温度场的影响,说明了其解的重要特性.研究表明,随着磁场参数的增大,速度和热边界层厚度变小了.与Newton流体相比较,微极流体的剪应力和传热率出现明显的减少,这对聚合物生产过程中流体的流动和热量控制是有益的.Abstract: The problem of two dimensional stagnation point flow of an electrically conducting micropolar fluid impinging normally on a heated surface in the presence of a uniform transverse magnetic field was analyzed.The governing continuity,momentum,angular momentum,and heat equations together with the associated boundary conditions were reduced to dimensionless form using suitable similarity transformations.The reduced self similar non-linear equations were then solved numerically by an algorithm based on finite difference discretization.The results were further refined by Richardson's extrapolation.The effects of the magnetic parameter,the micropolar parameters,and the Prandtl number on the flow and temperature fields were predicted in tabular and graphical forms to show the important features of the solution.The study shows that the velocity and thermal boundary layers become thinner as the magnetic parameter is increased.The micropolar fluids display more reduction in shear stress as well as heat transfer rate than that exhibited by Newtonian fluids,which is beneficial in the flow and thermal control of polymeric processing.
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