Reynolds Number Effects on Particle Dispersion and Deposition in Turbulent Square Duct Flows

A Reynolds-averaged Navier-Stokes (RANS) approach, coupled with a Lagrangian particle tracking technique, has been used to predict particle dispersion and deposition in square duct flows with a range of Reynolds numbers. Results for spherical particles over a range of sizes have been compared with predictions based on large eddy simulation (LES) under the assumption of one-way coupling. In general, there is reasonable agreement between the two techniques in regards to the effect of Reynolds number on dispersion and deposition, with the deposition rate increasing with Reynolds number. The main difference between the two approaches is in the dispersion of larger particles, with RANS predicting less dispersion across the duct. These differences are most likely attributable to the method used for deriving instantaneous fluid velocities from RANS solutions.