信息科学技术学院数学系学术讲座(五十一)

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 regardedas elastic potential energy. Motivated by this observation, we further use the well-known minimum potential energy principle toexplain the physical meaning of the stability/instability criteria in the NMRT problem. As a result of the analysis, we further extendthe results on the NMRT problem to the stratified MHD fluid case. We point out that our magnetic inhibition theory can be used to explainthe inhibition phenomenon of other flow instabilities, such as thermal instability, magnetic buoyancy instability, and so on, by impressed magneticfields 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 EquationsJ. Funct. Anal.J. Math. Pures Appl.J Differ. EquationsJ. Math. Fluid Mech.SIAM J. App. Math.SCI学术杂志上发表数学论文30多篇。

时间:20181130日(周五)晚上730

地点:南海楼224

  

热烈欢迎广大师生参加!

  

  

信息科学技术学院

20181129