Turbulence modulation for gas – particle flow in vertical tube and horizontal channel using four-way Eulerian–Lagrangian approach

Turbulence modulation of gas–solid flow in vertical tube and horizontal channel in dilute and moderately dense suspensions is investigated numerically using a four way Eulerian–Lagrangian approach. Low Reynolds number k–l model is used for analyzing the fluid phase motion. A new model is presented based on a source-term formulation, which can predict fluid phase turbulence augmentation due to the presence of large particles and damping of turbulence due to small particles in the core of the channel and tube. Particle–particle and particle–wall collisions are simulated based on a deterministic approach, and coupling terms representing the fluid–particle interactions are also taken into account. The predicted fluid mean velocity and turbulence intensity profiles are in good agreement with the available experimental data. Additional numerical simulation results for variation of the eddy viscosity, turbulence production and dissipation are also presented for different values of loading ratios.