Matura P, Lücke M
Institut für Theoretische Physik, Universität des Saarlandes, D-66041 Saarbrücken, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Aug;80(2 Pt 2):026314. doi: 10.1103/PhysRevE.80.026314. Epub 2009 Aug 21.
We have investigated the influence of a time-periodic and spatially homogeneous magnetic field on the linear stability properties and on the nonlinear response of a ferrofluid layer heated from below and from above. A competition between stabilizing thermal and viscous diffusion and destabilizing buoyancy and Kelvin forces occurs. Floquet theory is used to determine the stability boundaries of the motionless conductive state for a harmonic and subharmonic response. Full numerical simulations with a finite difference method were made to obtain nonlinear convective states. The effect of low- and high-frequency modulation on the stability boundaries as well as on the nonlinear oscillations that may occur is investigated.
我们研究了时间周期且空间均匀的磁场对从下方和上方加热的铁磁流体层的线性稳定性特性以及非线性响应的影响。稳定的热扩散和粘性扩散与不稳定的浮力和开尔文力之间存在竞争。利用弗洛凯理论确定静止传导状态对于谐波和亚谐波响应的稳定性边界。采用有限差分法进行了全数值模拟以获得非线性对流状态。研究了低频和高频调制对稳定性边界以及可能出现的非线性振荡的影响。
