Towards molecularly derived constitutive equations for complex fluids via systematic coarse-graining procedure

摘要

We here present a systematic coarse-graining method that is not only applicable to nonequilbrium dynamics but that also allows us to derive closed-form and thermodynamically consistent constitutive equations for complex fluids starting from microscopic models. A first and essential ingredient of the proposed approach is thermodynamically guided simulations within a consistent coarse-graining scheme. In addition to this new type of multiscale simulations, we reconstruct the building blocks that constitute the thermodynamically consistent coarse-grained model. We illustrate the method for low-molecular polymer melts, which are subject to different imposed flow fields. The constitutive equation we obtain shows rheological behavior including shear thinning, normal stress differences, and elongational viscosities in good agreement with reference results.