Investigation of particulate suspensions in generalised hydrodynamic dissipative particle dynamics using a spring model

Investigation of particulate suspensions in generalised hydrodynamic dissipative particle dynamics using a spring model

In the DPD simulation of particulate suspensions, the viscosity of the solvent phase is typically estimated by a non-equilibrium approach, where the fluid is subjected to a flow process (a shear flow), and the local stress and shear rate tensors are calculated; the obtained values (shear stress/shear rate) are then used in calculating the particulate fluid rheology, for example the ratio of the suspension to the matrix viscosity (reduced/relative viscosity) for a given volume fraction of the suspended phase. However, when suspended particles are added, an additional length scale is introduced into the solvent system and this may affect the solvent’s macroscopic properties. In this study, a particulate suspension is simulated using a spring model, and the solvent’s viscosity is estimated taking into account the finite-size effect (i.e., in the generalised hydrodynamic regime, as hydrodynamics of an integrable system) to produce improved results. Furthermore, it is observed that the simulation results are also affected by the repulsion strength and an appropriate high value of this coefficient, where the actual solvent viscosity in the hydrodynamic limit is still kept close to the input viscosity, can lead to a further improvement. New results are presented and compared with existing data.

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