摘要
电磁力(Lorentz力)可以改变弱导电流体边界层的结构,从而影响物体受力状况。该文将电磁激活板包覆在圆柱表面,置于弱电解质溶液中,从实验上测试并分析了Lorentz力对圆柱所受阻力的影响。为了揭示其影响过程的内在机理,对此现象进行了细致的数值研究,着重讨论了Lorentz力对圆柱阻力的各种组成部分的因素,揭示了Lorentz力主要通过改变圆柱表面涡量梯度及涡量来影响圆柱受力变化的内在过程。结果表明,在一定范围内,随着Lorentz力的增大,圆柱的表面涡量增大,流体分离点后移,表面涡量,阻力的振动幅度减小至零,圆柱所受阻力减小。
The structure of the flow boundary layer of a body in a low-conducting electrolytic fluid can be modified by the electro-magnetic body forces （ Lorentz forces）, and leads to a variation of the force experienced by the body. In present paper, the effect of Lorentz force on the cylinder force has been investigated experimentally and numerically. The circular cylinder covered with electrodes and magnetics on its surface was put in a low-conducting electrolytic flow. Based on the equations of magnetic and electric fields, and the formula of flow, thc influences of Lorentz force have been calculated numerically. It is found that the influencing factors include the direct effect of the force of the cylinder, indirect effect of the force by changing the flow, and holistic effect of the force modified by the Lorentz force. The numerical results obtained for the force of the cylinder agree well with the corresponding experimental results. When the Lorentz force smaller than a critical value increases, a raise of vorticity distribution along the surface of the cylinder occurs, the separation point of the flow moves backward, and the oscillation and period of vorticity, drag force coefficient distribution along the surface of the cylinder decrease gradually.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2007年第6期766-773,共8页
Chinese Journal of Hydrodynamics
