论文标题
集中在天体物理盘中非线性偏心波。 ii。激发和阻尼紧紧的波浪
Focusing of nonlinear eccentric waves in astrophysical discs. II. Excitation and damping of tightly-wound waves
论文作者
论文摘要
在本文中，我基于平均拉格朗日方法的whitham方法，发展了天体物理盘中紧密缠绕（高度扭曲的）偏心波的非线性理论。通过使用伪拉格朗日，该理论中包括粘性耗散。这项工作是Lee \＆Goodman开发的3D光盘的理论的扩展，并增加了粘度。我确认线性紧密的偏心波太稳了，并且由于剪切粘度的存在而感到兴奋，并显示了弱非线性波的持续存在。我发现当波变得充分非线性时，波浪会被剪切粘度阻尼，这是先前在颗粒盘中发现的结果。另外，我将该模型的结果与黑洞盘内部区域中传播区域的偏心波的最新模拟进行了比较，并表明在边缘稳定的轨道附近可以强烈抑制ingo的偏心波，从而导致圆盘密度的Azimuthal变化几乎圆形圆盘。
In this paper I develop a nonlinear theory of tightly-wound (highly twisted) eccentric waves in astrophysical discs, based on the averaged Lagrangian method of Whitham. Viscous dissipation is included in the theory by use of a pseudo-Lagrangian. This work is an extension of the theory developed by Lee \& Goodman to 3D discs, with the addition of viscosity. I confirm that linear tightly-wound eccentric waves are overstable and are excited by the presence of a shear viscosity and show this persists for weakly nonlinear waves. I find the waves are damped by shear viscosity when the wave become sufficiently nonlinear, a result previously found in particulate discs. Additionally I compare the results of this model to recent simulations of eccentric waves propagating in the inner regions of black hole discs and show that an ingoing eccentric wave can be strongly damped near the marginally stable orbit, resulting in a nearly circular disc with a strong azimuthal variation in the disc density.
