Palla Pier Luca, Pierleoni Carlo, Ciccotti Giovanni
Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato Ca, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Aug;78(2 Pt 1):021204. doi: 10.1103/PhysRevE.78.021204. Epub 2008 Aug 29.
Nonequilibrium molecular dynamics (NEMD) calculations of the bulk viscosity of the triple point Lennard-Jones fluid are performed with the aim of investigating the origin of the observed disagreement between Green-Kubo estimates and previous NEMD data. We show that a careful application of the Doll's perturbation field, the dynamical NEMD method, the instantaneous form of the perturbation and the "subtraction technique" provides a NEMD estimate of the bulk viscosity at zero field in full agreement with the value obtained by the Green-Kubo formula. As previously reported for the shear viscosity, we find that the bulk viscosity exhibits a large linear regime with the field intensity.
为了研究格林-库博估计值与先前非平衡分子动力学（NEMD）数据之间存在差异的原因，我们对三相点伦纳德-琼斯流体的体黏度进行了非平衡分子动力学计算。我们表明，仔细应用多尔微扰场、动力学NEMD方法、微扰的瞬时形式和“减法技术”，可以得到零场下体黏度的NEMD估计值，该值与通过格林-库博公式获得的值完全一致。正如之前关于剪切黏度的报道一样，我们发现体黏度随场强呈现出较大的线性区域。
