Eddy-resolving Reynolds stress modeling of particle-laden flows using a multiphase Euler–Lagrange approach

A novel unsteady RANS-based Reynolds stress model, appropriately sensitized to account for the fluctuating turbulence, is coupled with the multiphase Euler–Lagrange approach to simulate wall-bounded particle-laden flows characterized by a wide range of flow and particle parameters, including flow and particle Reynolds numbers, particle Stokes number, particle-to-fluid density ratio, and particle mass loading ratio. The interaction between the fluid and particle phases is studied within the framework of one-, two- and four-way coupling algorithms in accordance with the investigations providing a reference database. In the case of four-way coupling, turbulence modulation is accurately predicted without the need for additional models to account for particle dispersion. The predictive capabilities of the present turbulence model, referred to as the Improved Instability-Sensitive Reynolds Stress Model (IIS-RSM), coupled with the Lagrangian particle tracking approach are evaluated in direct comparison with the results of various computational and experimental benchmark studies performed in differently characterized channel and pipe flow configurations, including flow separation in a backward-facing step geometry, with particular emphasis on the flow localities subjected to enhanced flow strain in the near-wall region and the separated shear layer. Very good agreement of the IIS-RSM-related results with reference data is obtained for the mean flow and turbulence properties of both phases. • A sensitized Reynolds stress model is applied to differently configured particle-laden wall-bounded flow configurations characterized by a wide range of flow and particle parameters. • The study focuses on the influence of the flow Reynolds numbers, particle Stokes numbers, particle-to-fluid density ratio, and particle mass loading ratio on the associated turbulence correlations. • Emphasis is placed on the predictive performance of a novel unsteady RANS- based eddy-resolving Reynolds stress model, coupled with the multiphase Euler–Lagrange approach. • The mean flow and the associated turbulence correlations are subject to a significant deviation from the equilibrium conditions caused by the interacting particles. • The manipulation of the flow field due to the presence of the disperse phase is characterized by an alternating redistribution of the turbulence energy among the stress components and the resulting anisotropy level enhancement.