Abstract
<jats:p>Consistent predictions across polymer chain models of different resolutions remain challenging due to configuration-dependent, fluctuating hydrodynamic interactions (HI). In this study, we perform Brownian dynamics simulations with HI, using fine-grained bead–rod chains and coarse-grained bead–spring counterparts. Large deviations are observed in both rheological and conformational predictions. However, the coarse-grained simulations, being orders of magnitude faster, are highly desirable. Here, we present a modification that brings the rheological predictions significantly closer to those for fine-grained chains. In rheological flow fields, the bead hydrodynamic diameter is increased proportionally to the mean spring stretch, as supported by an analysis of hydrodynamic interactions between stretched chain segments. Thus, the consecutive beads continue to interact hydrodynamically even as the springs get stretched. Three different averaging protocols–the arithmetic mean, root-mean-square, and harmonic mean–yield similar trends.</jats:p>