Santamaría-Holek I, Barrios G, Rubi J M
Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito exterior de Ciudad Universitaria, 04510 Distrito Federal, Mexico.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Mar;79(3 Pt 1):031201. doi: 10.1103/PhysRevE.79.031201. Epub 2009 Mar 6.
We study the shear-induced diffusion effect and the transition to irreversibility in suspensions under oscillatory shear flow by performing an analysis of the entropy production associated with the motion of the particles. We show that the Onsager coupling between different contributions to the entropy production is responsible for the scaling of the mean square displacement on particle diameter and applied strain. We also show that the shear-induced effective diffusion coefficient depends on the volume fraction, and use lattice-Boltzmann simulations to characterize the effect through the power spectrum of particle positions for different Reynolds numbers and volume fractions. Our study gives a thermodynamic explanation of the transition to irreversibility through a pertinent analysis of the second law of thermodynamics.
我们通过对与颗粒运动相关的熵产生进行分析，研究了振荡剪切流作用下悬浮液中的剪切诱导扩散效应以及向不可逆性的转变。我们表明，对熵产生的不同贡献之间的昂萨格耦合是均方位移与颗粒直径和施加应变之间标度关系的原因。我们还表明，剪切诱导有效扩散系数取决于体积分数，并使用格子玻尔兹曼模拟通过不同雷诺数和体积分数下颗粒位置的功率谱来表征这种效应。我们的研究通过对热力学第二定律的相关分析，给出了向不可逆性转变的热力学解释。
