数学系学术讲座(五十一)

发布时间: 2018-11-29 来源: 信息科学技术学院

题  目:On Magnetic Inhibition Theory in Non-resistive Magnetohydrodynamic Fluids

内容简介:We investigate why the non-slip boundary condition for the velocity, imposed in the direction of impressed magnetic fields, can contribute to the magnetic inhibition effect based on the magnetic Rayleigh--Taylor (abbr. NMRT) problem in nonhomogeneous incompressible non-resistive magnetohydrodynamic (abbr. MHD) fluids. Exploiting an infinitesimal method in Lagrangian coordinates, the idea of (equivalent) magnetic tension, and the differential version of magnetic flux conservation, we give an explanation of physical mechanism for the magnetic inhibition phenomenon in a non-resistive MHD fluid. Moreover,  we find that the magnetic energy in the non-resistive MHD fluid depends on the displacement of fluid particles, and thus can be regarded  as elastic potential energy. Motivated by this observation, we further use the well-known minimum potential energy principle to  explain the physical meaning of the stability/instability criteria in the NMRT problem. As a result of the analysis, we further extend  the results on the NMRT problem to the stratified MHD fluid case. We point out that our magnetic inhibition theory can be used to explain  the inhibition phenomenon of other flow instabilities, such as thermal instability, magnetic buoyancy instability, and so on, by impressed magnetic  fields in non-resistive MHD fluids.

报告人:福州大学  江飞  教授

报告人简介:福州大学数学与计算机科学学院信息与计算科学系教授,博士生导师。主要学习与研究流体动力学中各类偏微分方程组的适定性问题及解的性态。已在Arch. Rational Mech. Anal.,Adv. Math.,Comm. Partial Differential Equations,J. Funct. Anal.,J. Math. Pures Appl.,J Differ. Equations,J. Math. Fluid Mech.,SIAM J. App. Math.等SCI学术杂志上发表数学论文30多篇。

时  间:2018年11月30日(周五)晚上7:30始

地  点:南海楼224室

 

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信息科学技术学院

2018年11月29日