Numerical Simulation of Instability in Wind Accretion Flow

我们考虑了一个紧密的双星系统，它由一个紧凑的物体（如黑洞、中子星或白矮星）和一个伴星（如巨星或主序星）组成。我们对其中的吸积流进行了数值模拟。有两种类型的吸积流，即风吸积流和吸积盘。我们考虑了这两种情况。在风积方面，我与川崎重工的e.s ima，马克斯-普朗克研究所的u.a anzer和g.b erner，卡迪夫大学的h.b ffin合作。我们假定流动被限制在一个厚度恒定的区域内，而且气体是等温的。我们发现水流非常不稳定，吸积柱像蛇一样摆动。这与瑞士研究人员对我们早期工作提出的批评相反。这股气流一开始几乎是稳定的，在致密天体后面形成了一个很长的吸积柱。当我们继续计算足够长的时间时，柱开始波动，振幅随时间增长。偶尔会在物体周围形成吸积盘。我们还进行了一些相关问题的数值模拟，如三维吸积盘，太阳风与星际物质之间的相互作用，以及超新星的爆炸。

We considered a close binary system consisted by a compact object, such as a black hole, a neutron star or a white dwarf, and a companion star, such as a giant or a main sequence star. And we performed numerical simulations of accretion flows in it. There are two types of accretion flows, i.e. a wind accretion flow and an accretion disc. We considered both cases.As to wind accretion, I cooperated with E.Shima at Kawasaki Heavy Industries, U.Anzer and G.Boerner at Max-Planck Institute and H.Boffin at Cardiff University. We assume that the flow is restricted within a region of constant thickness and also gas to be isothermal. We found that the flow was very unstable and that the accretion column waved like a snake. This is contrary to the criticism posed by Swiss researchers to our earlier works.The flow is nearly steady at first and forms a very long accretion column behind the compact object. When we continue the calculation long enough, the column begins to wave and the amplitude grows with time. Occasionally an accretion disc is formed about the object.We also performed number of numerical simulations of relating matters, such as three dimensional accretion disc, the interaction between the solar wind and an interstellar matter, and explosion of a supernova.