Assessment of particle-tracking models for dispersed particle-laden flows implemented in OpenFOAM and ANSYS FLUENT

Abstract

In the present study two benchmark problems for turbulent dispersed particle-laden flow are investigated with computational fluid dynamics (CFD). How the CFD programs OpenFOAM and ANSYS FLUENT model these flows is tested and compared. The numerical results obtained with Lagrangian–Eulerian (LE) point-particle (PP) models for Reynolds-averaged Navier–Stokes (RANS) simulations of the fluid flow in steady state and transient modes are compared with the experimental data available in the literature. The effect of the dispersion model on the particle motion is investigated in particular, as well as the order of coupling between the continuous carrier phase and the dispersed phase. First, a backward-facing step (BFS) case is validated. As a second case, the confined bluff body (CBB) is used. The simulated fluid flows correspond well with the experimental data for both test cases. The results for the dispersed solid phase reveal a good accordance between the simulation results and the experiments. It seems that particle dispersion is slightly under-predicted when ANSYS FLUENT is used, whereas the applied solver in OpenFOAM overestimates the dispersion somewhat. Only minor differences between the coupling schemes are detected due to the low volume fractions and mass loadings that are investigated. In the BFS test case the importance of the spatial dimension of the numerical model is demonstrated. Even if it is reasonable to assume a two-dimensional fluid flow structure, it is crucial to simulate the turbulent particle-laden flow with a three-dimensional model since the turbulent dispersion of the particles is three-dimensional.

Keywords

• CFD
• Lagrangian-Eulerian approach
• backward-facing step
• confined bluff body
• stochastic dispersion model