Earthquake Research Institute, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Department of Physics, Kyoto University, Kitashirakawa Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
Phys Rev E. 2018 Apr;97(4-1):042902. doi: 10.1103/PhysRevE.97.042902.
Rheology of a dilute cohesive granular gas is theoretically and numerically studied. The flow curve between the shear viscosity and the shear rate is derived from the inelastic Boltzmann equation for particles having square-well potentials in a simple shear flow. It is found that (i) the stable uniformly sheared state only exists above a critical shear rate and (ii) the viscosity in the uniformly sheared flow is almost identical to that for uniformly sheared flow of hard core granular particles. Below the critical shear rate, clusters grow with time, in which the viscosity can be approximated by that for the hard-core fluids if we replace the diameter of the particle by the mean diameter of clusters.
本文从具有方阱势能的颗粒的非弹性 Boltzmann 方程出发，对稀合同质颗粒气体的流变学进行了理论和数值研究。推导出了剪切粘度和剪切率之间的流动曲线。结果表明：（i）稳定的均匀剪切状态仅存在于临界剪切率以上；（ii）均匀剪切流动中的粘度与硬球颗粒的均匀剪切流动中的粘度几乎相同。在临界剪切率以下，团簇随时间增长，此时，如果我们用团簇的平均直径代替颗粒的直径，那么粘度可以用硬球流体的粘度来近似。
