Donkó Z, Goree J, Hartmann P
Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, PO Box 49, H-1525 Budapest, Hungary.
Phys Rev E Stat Nonlin Soft Matter Phys. 2010 May;81(5 Pt 2):056404. doi: 10.1103/PhysRevE.81.056404. Epub 2010 May 14.
The viscoelastic properties of strongly coupled Yukawa liquids are characterized by computing the complex shear viscosity η(ω) . This is done using three methods of molecular-dynamics simulation: equilibrium, nonequilibrium, and Langevin dynamics, all with a mutually repulsive Yukawa interparticle potential. A change from viscous to elastic response is observed with increasing frequency, as well as a decrease of the magnitude of the viscosity with increasing frequency. The Langevin simulation reveals that the dependence of the complex viscosity on the friction has a different character for hot and cool liquids. At ω=0 , we find that as friction increases, the viscosity diminishes at high temperature but increases at low temperature. In addition to finding its frequency dependence, we also derive the wave-number (length-scale) dependence of the shear viscosity.
通过计算复剪切粘度η(ω)来表征强耦合 Yukawa 液体的粘弹性特性。这是使用三种分子动力学模拟方法完成的：平衡动力学、非平衡动力学和朗之万动力学，所有这些方法都采用相互排斥的 Yukawa 粒子间势。随着频率增加，观察到从粘性响应到弹性响应的转变，以及粘度大小随频率增加而降低。朗之万模拟表明，对于热液体和冷液体，复粘度对摩擦的依赖性具有不同的特征。在ω = 0 时，我们发现随着摩擦增加，高温下粘度减小，而低温下粘度增加。除了发现其频率依赖性外，我们还推导了剪切粘度的波数（长度尺度）依赖性。
