球对称吸积的数值模拟

Numerical Simulation on Spherical Accretion Flow

黑洞球对称吸积存在稳恒态的亚声速-跨声速解,该解对应最大可能吸积率的稳恒态吸积流.在本文中,我们应用计算流体动力学方法成功得到了跨声速吸积流的整体解.该方法的优点在于,吸积流体从初态沿着时间方向不断推进到稳恒态的过程是物理的、真实的演化过程.另外,计算流体力学方法发展得比较成熟,为我们求解跨声速吸积流提供了非常强大的工具.除了球对称吸积过程,计算流体力学的方法也应该同样适用于求解辐射无效吸积流以及超Eddington吸积流的整体动力学结构.

There exists a steady ,spherical and subsonic-transonic accretion flow onto a central black hole ,which corresponds to the maximum possible steady accretion mode .In the work ,in the light of the computational fluid dynamics , the global dynamics of the steady , spherical subsonic-transonic accretion has been successfully obtained .There are two advantages of this method .First ,during the time-marching process from the initial state to the steady state , the evolutionary process is physical and realistic .Second , the computational fluid dynamics has been developed more maturely ,which provides us with a very powerful tool to solve the transonic accretion flow .In addition to the spherically symmetric accretion ,the method of computational fluid mechanics should be also suitable for solving the global dynamics of the radiatively inefficient accretion flow and super-Eddington accretion flow .