Study of a Dissipative Particle Dynamics Based Approach for Modeling Suspensions.
Study of a Dissipative Particle Dynamics Based Approach
for Modeling Suspensions.
Martys, N. S.
Journal of Rheology, Vol. 49, No. 2, 401-424,
suspensions; tests; simulation; rheology; equations;
In this paper, a dissipative particle dynamics (DPD)
based approach for modeling suspensions is examined. A
series of tests is applied comparing simulation results
to well established theoretical predictions. The model
recovers the dilute limit intrinsic viscosity prediction
of Einstein and provides reasonable estimates of the
Huggins coefficient for semidilute suspensions. At
higher volume fractions, it was necessary to explicitly
include lubrication forces into the algorithm as the
usual DPD interactions are too weak to prevent overlaps
of the rigid bodies and account for other related
effects due to lubrication forces. Results were then
compared with previous studies of dense hard sphere
suspensions using the Stokesian dynamics method and
experimental data. Comparison of relative viscosity
values determined from strain controlled shearing versus
stress controlled shearing simulations are also given.
The flow of spheroidal objects is studied. The rotation
of a single spheroid under shear is consistent with the
predictions of Jeffery. Simulations of sheared spheroids
at higher volume fractions produce an apparent nematic
phase. An example is given of the application of DPD to
model flow in another geometry, gravitational driven
flow between parallel cylinders, which is of practical