Three-dimensional Magnetohydrodynamic Numerical Simulations of Cloud-Wind Interactions
Three-dimensional Magnetohydrodynamic Numerical Simulations of Cloud-Wind Interactions
复制标题
云风相互作用的三维磁流体动力学数值模拟
DOI：
10.1086/317130
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
T. Jones
中科院分区：
文献类型：
--
作者：
G. Gregori;F. Miniati;D. Ryu;T. Jones
我们目前的结果从三维数值模拟调查云风相互作用的磁流体动力学。初始云是球形的，而磁场是均匀的，并且横向于云的运动。一个简化的分析模型，描述了在云的前面的磁能演化的开发和模拟结果进行比较。此外，它被发现的云与磁化星际介质的相互作用的结果在形成一个高度结构化的磁尾。云尾流中的磁通量组织成通量绳，当相反极性的场线在对称轴附近靠近在一起时，就会形成重联电流片。与此同时，在云的前缘，由于那里发生的磁力线拉伸，磁压强烈增强。这对云的后续演变有重要的动力学影响，因为一些不稳定的模式往往会被强烈增强。
We present results from three-dimensional numerical simulations investigating the magnetohydrodynamics of cloud-wind interactions. The initial cloud is spherical, while the magnetic field is uniform and transverse to the cloud motion. A simplified analytical model that describes the magnetic energy evolution in front of the cloud is developed and compared with simulation results. In addition, it is found that the interaction of the cloud with a magnetized interstellar medium results in the formation of a highly structured magnetotail. The magnetic flux in the wake of the cloud organizes into flux ropes, and a reconnection current sheet is developed as field lines of opposite polarity are brought close together near the symmetry axis. At the same time magnetic pressure is strongly enhanced at the leading edge of the cloud from the stretching of the field lines that occurs there. This has an important dynamical effect on the subsequent evolution of the cloud, since some unstable modes tend to be strongly enhanced.