  This study is concerned with the statistics of vertical turbulent channel
flow laden with inertial particles for two different volume concentrations
($\Phi_{V} = 3 \times 10^{-6}$ and $\Phi_{V} = 5 \times 10^{-5}$) at a Stokes
number of $St^{+} = 58.6$ based on viscous units. Two independent direct
numerical simulation models utilizing the point-particle approach are compared
to recent experimental measurements, where all relevant nondimensional
parameters are directly matched. While both numerical models are built on the
same general approach, details of the implementations are different,
particularly regarding how two-way coupling is represented. At low volume
loading, both numerical models are in general agreement with the experimental
measurements, with certain exceptions near the walls for the wall-normal
particle velocity fluctuations. At high loading, these discrepancies are
increased, and it is found that particle clustering is overpredicted in the
simulations as compared to the experimental observations. Potential reasons for
the discrepancies are discussed. As this study is among the first to perform
one-to-one comparisons of particle-laden flow statistics between numerical
models and experiments, it suggests that continued efforts are required to
reconcile differences between the observed behavior and numerical predictions.
