Using RANS turbulence models and Lagrangian approach to predict particle deposition in turbulent channel flows

摘要

This study investigates the capability and accuracy of three Reynolds-Averaged Navier-Stokes (RANS) turbulence models, i.e. a Reynolds stress model (RSM), a RNG k-e model, and an SST k-w model in the prediction of particle deposition in vertical and horizontal turbulent channel flows. The particle movement was simulated using a Lagrangian-based discrete random walk (DRW) model. The performances of the three RANS turbulence models with and without near-wall turbulence corrections were evaluated. A new modification method for turbulence kinetic energy was proposed for the RNG k-e model and the SST k-w model. The results were compared with previous experimental data, empirical equation as well as simulation outcomes. It is found that the isotropic SST k-w model and the RSM model can successfully predict the transition from the diffusion region to the inertia-moderated region. The RNG k-e model with near-wall modifications can also reflect the V-shape deposition curve although without modifications it greatly over-predicts the deposition velocity and shows an almost straight deposition line. For all of the three turbulence models, application of near-wall corrections is able to improve the simulation results to different extents.