Effect of Weight Functions on the Dynamics and Rheology of Dilute Polymer Solutions in Dissipative Particle Dynamics Simulations

Dissipative particle dynamics (DPD) is a mesoscale simulation technique that has shown promise for studying polymer solutions, particularly in complex flow geometries. However, its application in rheological studies of polymer solutions remains limited compared to Brownian dynamics (BD) simulations. This is partly due to lack of investigations of the effect of modeling parameters on rheological results, in flow fields. This study investigates the influence of the weight function parameter in DPD simulations on the behavior of dilute polymer solutions, comparing the conventional value with , which has been suggested to better mimic liquid‐like behavior. We perform detailed DPD simulations at equilibrium and under flow conditions, including both extensional and shear flows, using a highly resolved polymer chain model. Our results show that while the equilibrium chain size predictions are nearly identical for both values, the dynamics differ significantly. Specifically, results in slower chain relaxation times and suppresses excluded volume effects. Drag forces with are larger, leading to higher chain stretch at moderate flow rates. With start‐up extension, the time distribution for unraveling with remains significantly narrow, with no outlier configurations with delayed stretching. In shear flows, the end‐over‐end tumbling dynamics is slower with , with the chain spending significantly larger time in stretched state at moderate shear rates. However, the chain size predictions (averaged over conformations and time) and trends remain similar. However, noting the overpowering of HI, leading to the suppression of EV effects at equilibrium and also an extremely narrow time distribution for unraveling, with no outlier and delayed stretching (as seen in experiments), the results with (conventional DPD) appears more consistent than . Thus, our findings indicate that may be more appropriate for rheological simulations of dilute polymer solutions using DPD simulations.