Three-dimensional MHD duct flows with strong transverse magnetic fields Part 1. Obstacles in a constant area channel
Three-dimensional MHD duct flows with strong transverse magnetic fields Part 1. Obstacles in a constant area channel
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具有强横向磁场的三维 MHD 管道流第 1 部分：恒定面积通道中的障碍物
DOI：
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发表时间：
1968
影响因子：
3.7
通讯作者：
G. Ludford
中科院分区：
文献类型：
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作者：
J. Hunt;G. Ludford
本文分析了导电流体在横向磁场作用下的不可压缩三维流动，假设横向磁场足够强，使相互作用参数N(=M2/R)[GT]1，其中M为哈特曼数，R为雷诺数。我们还假设R[GT]1和Rm(磁雷诺数)[LT]1，从而使理论的实验验证成为可能。主要结果是：(I)当一个厚体被放置在带有非导电墙的平行通道中时，其上的流动高度依赖于该物体的导电性，这是一种令人惊讶的方式。如果物体是不导电的，则在环绕物体且与磁场平行的圆柱体内没有流动；圆柱体外部的流动是平面的和势能的，并以直角进入或离开该圆柱体的表面剪切层。如果物体是导电的，就有可能流过它，并且在圆柱体外部和内部具有不同的性质。(Ii)当不导电平板放置在该等渠道内时，水流不会受阻。如果板沿流动方向拉长，则其上方的流动与Hasimoto(1960)的计算结果相同，如果与流动成直角拉长，则与Dix(1963)的计算结果相同。在我们的分析中特别感兴趣的是出现在这些流动中的两种层，第一种是哈特曼边界层，它被证明在三维情况下对核心流动的涡度具有控制影响，类似于旋转流体流动中的埃克曼层。第二种类型，外接圆柱处的自由剪切层，由于其内部结构和对外部流动的影响而令人感兴趣。
This paper is an analysis of incompressible three-dimensional flows of electrically conducting fluids under the action of transverse magnetic fields which are assumed to be sufficiently strong that the interaction parameter N (= M2/R) [Gt ] 1, where M is the Hartmann number and R is the Reynolds number. We also assume that R [Gt ] 1 and Rm (magnetic Reynolds number) [Lt ] 1, so that experimental verification of the theory may be possible. The main results are: (i) when a thick body is placed in a parallel-sided channel with non-conducting walls the flow over it is highly dependent on the conductivity of the body, in a surprising way. If the body is non-conducting, there is no flow within that cylinder which circumscribes the body and is parallel to the magnetic field; outside the cylinder the flow is plane and potential and enters or leaves the surface shear layer of this cylinder at right angles. If the body is conducting, flow over it is possible and is of a different nature outside and inside the cylinder. (ii) When a non-conducting flat plate is placed in such a channel no blocking of the flow occurs. If the plate is elongated in the flow direction, the flow over it becomes identical to that calculated by Hasimoto (1960) and, if elongated at right angles to the flow, becomes identical to that calculated by Dix (1963). Of particular interest in our analysis are the two types of layer which occur in these flows, the first being the Hartmann boundary layer, which is shown to have a controlling influence on the vorticity of the core flow in three-dimensional situations analogous to that of the Eckman layer in rotating-fluid flows. The second type, the free shear layer at the circumscribing cylinder, is of interest because of its internal structure and effect on the external flow.