Turbulent convection and pulsation stability of stars - I. Basic equations for calculations of stellar structure and oscillations
Turbulent convection and pulsation stability of stars - I. Basic equations for calculations of stellar structure and oscillations
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恒星的湍流对流和脉动稳定性——一、恒星结构和振荡计算的基本方程
DOI：
10.1093/mnras/stv1170
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
熊大闰
中科院分区：
文献类型：
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作者：
熊大闰
从流体动力学方程出发，根据经典的雷诺湍流处理方法，建立了一套平均流动的流体动力学方程和一套湍流速度和温度波动的自相关和相互相关的动力学方程。这两组方程的结合产生了一个完整的、自洽的数学表达式，为计算恒星的结构和振荡做好了准备。本文简要介绍了湍流对流的非局域性和各向异性，并对算法中包含的三个对流参数c(1)、c(2)和c(3)进行了定义和标定。利用非局部对流理论，用数值解证明了对流包络的结构和非绝热线性振荡的主要特征。在对流参数的选择和模型的脉动不稳定性方面做了大量的工作，结果表明，在三个参数(c(1)、c(2)和c(3)的大范围内，脉动稳定性的主要性质保持不变。
Starting from hydrodynamic equations, we have established a set of hydrodynamic equations for average flow and a set of dynamic equations of auto- and cross-correlations of turbulent velocity and temperature fluctuations, following the classic Reynold's treatment of turbulence. The combination of the two sets of equations leads to a complete and self-consistent mathematical expressions ready for the calculations of stellar structure and oscillations. In this paper, non-locality and anisotropy of turbulent convection are concisely presented, together with defining and calibrating of the three convection parameters (c(1), c(2) and c(3)) included in the algorithm. With the non-local theory of convection, the structure of the convective envelope and the major characteristics of non-adiabatic linear oscillations are demonstrated by numerical solutions. Great effort has been exercised to the choice of convection parameters and pulsation instabilities of the models, the results of which show that within large ranges of all three parameters (c(1), c(2) and c(3)) the main properties of pulsation stability keep unchanged.