Abstract

The frequency dispersion has been studied for the dynamic viscosity coefficients determined on the basis of both the Smoluchowski equation, which describes the diffusion relaxation mechanism, and the Bhatnagar–Gross–Krook approximation, which leads to an exponential damping of the stress tensor in magnetic fluids. In the former case, the Green function, which enters into the integral parts of the transport coefficients, is a slowly damped function varying in accordance with the \({{t}^{{{{ - 3} \mathord{\left/ {\vphantom {{ - 3} 2}} \right. \kern-0em} 2}}}}\) law, which has been observed in many computer-assisted experiments. Here, the range of the frequency dispersion of viscosity coefficients is very wide as a consequence of the damping of relaxation fluxes according to the power law. In the latter case, the range of the frequency dispersion of the viscosity coefficients is narrow as a consequence of the exponential damping of the stress tensor and coincides with experimental data.

中文翻译：

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关于磁流体中的动态粘度系数和弛豫过程

摘要

已经研究了基于描述扩散弛豫机制的 Smoluchowski 方程和 Bhatnagar-Gross-Krook 近似确定的动态粘度系数的频率色散，这导致了磁性流体中应力张量的指数阻尼. 在前一种情况下，进入传输系数的整数部分的格林函数是一个缓慢衰减的函数，它根据\({{t}^{{{{ - 3} \mathord{\left/ {\vphantom {{ - 3} 2}} \right. \kern-0em} 2}}}}\)在许多计算机辅助实验中都观察到了这一定律。在这里，根据幂律，作为弛豫通量阻尼的结果，粘度系数的频散范围非常宽。在后一种情况下，由于应力张量的指数阻尼，粘度系数的频率分散范围很窄，并且与实验数据一致。