  The Lagrangian probability-density-function model, proposed in Part I for
dense particle-laden turbulent flows, is validated here against
Eulerian-Lagrangian direct numerical simulation (EL) data for different
homogeneous flows, namely statistically steady and decaying homogeneous
isotropic turbulence, homogeneous-shear flow and cluster-induced turbulence
(CIT). We consider the general model developed in Part I adapted to the
homogeneous case together with a simplified version in which the decomposition
of the phase-averaged (PA) particle-phase fluctuating energy into the spatially
correlated and uncorrelated components is not used, and only total exchange of
kinetic energy between phases is allowed. The simplified model employs the
standard two-way coupling approach. The comparison between EL simulations and
the two stochastic models in homogeneous and isotropic turbulence and in
homogeneous-shear flow shows that in all cases both models are capable to
reproduce rather well the flow behaviour, notably for dilute flows. The
analysis of the CIT gives more insights on the physical nature of such systems
and about the quality of the models. Results elucidate the fact that simple
two-way coupling is sufficient to induce turbulence, even though the granular
energy is not considered. Furthermore, first-order moments including velocity
of the fluid seen by particles can be fairly well represented with such a
simplified stochastic model. However, the decomposition into spatially
correlated and uncorrelated components is found to be necessary to account for
anisotropic energy exchanges. When these factors are properly accounted for as
in the complete model, the agreement with the EL statistics is satisfactory up
to second order.
