论文标题
关于相对论喷气机和积聚磁盘中的湍流粘度
On turbulent viscosity in relativistic jets and accretion disks
论文作者
论文摘要
湍流粘度的机制是研究湍流的核心问题。在积聚磁盘理论中也是这种情况，其中湍流被认为是促进磁盘中角动量向外运输的原因。在湍流中，涡流在其长度尺度上运输动量，提供了受质量夹带控制的粘度机理。我们早些时候提出了一个针对相对论喷气机的特定情况的夹带模型，该模型在射电星系3C31中。在本文中，我们进一步限制了模型参数。该模型（在非相关部分中）已成功测试与实验和实验数据，并在雷诺的自由混合层的应力上进行了模拟数据，并预测了Smagorinsky常数$ C_ \ MATHRM {S} \大约0.11 $，这与shear Flow的实验范围$ C_ \ MATHRM {s $ cogtrm {s $ c $ aighears compans一致，这是一致的。对于积聚盘，夹带模型允许我们得出与Shakura \＆Sunyaev的$α$ -MODEL中相同的增值质量率，而不会吸引动荡的运动粘度$ν_\ Mathrm {t} $，以及viscosity参数$α$ frac $ \ frac frac。 βS_\ MATHRM {t} \ frac {\ Mathrm {\ MathRM {v_t}^2} {C_ \ Mathrm {s}^2} $取决于电源$ $ s_ \ s_ \ mathrm {t}沿disk radius沿disk radius的温度斜率，$ t \ propto r^r^rm^rm^s_ qu {在湍流速度$ \ mathrm {v_t} $上。
The mechanism of turbulent viscosity is the central question in investigations of turbulence. This is also the case in the accretion disk theory, where turbulence is considered to be responsible for the outward transport of angular momentum in the accretion disk. In turbulent flows, vortices transport momentum over their length scales providing the mechanism of viscosity that is controlled by mass entrainment. We have earlier proposed an entrainment model for the particular case of the relativistic jets in the radio galaxy 3C31. In this paper, we further constrain the model parameters. The model (in the non-relativistic part) is successfully tested versus experimental and simulation data on the Reynolds stresses of free mixing layers and predicts the Smagorinsky constant $C_\mathrm{S} \approx 0.11$, which is consistent with the experimental range for shear flows $C_\mathrm{S} \approx 0.1-0.12$. For accretion disks, the entrainment model allows us to derive the same accretion mass rate as in the Shakura \& Sunyaev's $α$-model without appealing to the turbulent kinematic viscosity $ν_\mathrm{t}$, and the viscosity parameter $α$ derived in the form $\displaystyle α= -\frac{8}{3} βs_\mathrm{T} \frac{\mathrm{v_t}^2}{c_\mathrm{s}^2}$ depends on the power $s_\mathrm{T}$ of the temperature slope along the disk radius, $T\propto r^{s_\mathrm{T}}$, and quadratically on the turbulent velocity $\mathrm{v_t}$.
