2.5D magnetohydrodynamic simulation of the Kelvin-Helmholtz instability around Venus—Comparison of the influence of gravity and density increase
2.5D magnetohydrodynamic simulation of the Kelvin-Helmholtz instability around Venus—Comparison of the influence of gravity and density increase
复制标题
DOI：
10.1063/1.3682039
复制
发表时间：
2012-02
影响因子：
2.2
通讯作者：
M. Zellinger;U. Möstl;N. Erkaev;H. Biernat
中科院分区：
文献类型：
--
作者：
M. Zellinger;U. Möstl;N. Erkaev;H. Biernat
我们给出了2.5D开尔文-亥姆霍兹不稳定性及其涡旋的数值研究，其中假定了适合于非磁化行星周围情况的初始等离子体构型。用全变差递减Lax-Friedrichs算法数值求解理想磁流体力学方程组。我们的密度分布是这样的，质量密度向行星方向增加。密度越高，不稳定的增长率越小，因此对边界层有稳定作用。此外，我们在方程中加入了源项，使我们能够研究重力的影响。我们的结果表明，引力影响开尔文-亥姆霍兹不稳定性的演化。然而，效果并不是很显著。因此，我们得出结论，朝向金星的密度增加比重力更能稳定金星周围的边界层。
We present a numerical study of the 2.5D Kelvin-Helmholtz instability and its vortices, where an initial plasma configuration appropriate for the situation around unmagnetized planets is assumed. We solve the set of ideal magnetohydrodynamic equations numerically with the total variation diminishing Lax-Friedrichs algorithm. Our density profile is such that the mass density increases toward the planet. A high density leads to smaller growth rates of the instability and, thus, has a stabilizing effect for the boundary layer. Moreover, we include source terms in the equations, enabling us to study the influence of gravity. Our results show that gravity affects the evolution of the Kelvin-Helmholtz instability. However, the effect is not very significant. We thus conclude that the density increase toward the planet stabilizes the boundary layer around Venus more than gravity does.