Behavior of downward turbulent gas–solid flow through sudden expansion pipe

• CFD program based on Eulerian–Lagrangian approach is developed for simulation.
• Gas–solid flow simulation in sudden-expansion pipe is performed.
• Simulations using RANS with standard k-ε turbulence model are carried out.
• Successful results are presented via comparisons with published experimental work.
• Generated secondary losses and separation are discussed with different parameters.

The effects of solid-particles on downward turbulent-air flow through a pipe with sudden expansion are simulated by Eulerian–Lagrangian approach. Reynolds averaged Navier Stokes equations associated with standard k-ε turbulence model are used. Source terms are included to represent the effects of fluid–particle interactions and particle–particle collisions assuming non-deformed spherical shape particles. A FORTRAN code is developed based on the finite volume discretization with hybrid scheme to simulate the problem. Based on comparisons with published experimental work, the present code introduces good results that encourage the authors to extend the theoretical work considering different parameters. The performance of sudden expansion in the form of loss coefficient is studied at different particle sizes, mass loading ratios and Reynolds numbers. In light of the computational results, the finest particles can improve the performance of the sudden expansion, while the size of separation bubble increases.

Effect of coupling approach on the particles' trajectories.Figure optionsDownload as PowerPoint slide