A mathematical model of turbulence modulation in particle-laden pipe flows

This investigation is concerned with developing a model of the processes involved in turbulence modulation by relatively large particles in dilute gas-solid turbulent flows. The mathematical model, which focuses on two-way coupling, has been developed based on the work of Lightstone and Hodgson (Turbulence modulation in gas-particle flows: a comparison of selected models, " Can. J. Chem. Eng. 82, 2004, 209-219) to account for both enhancements and reductions in turbulent kinetic energy as well as the particle crossing trajectory effect. The underlying formulation scheme employs an Eulerian-Lagrangian reference frame, i.e. the carrier phase is considered as a continuum system, while the trajectories of individual particles are calculated using a Lagrangian framework. A random walk model is used to solve the particle motion equation. The proposed model, along with turbulence modulation models from the literature, is used to simulate a particle-laden vertical pipe flow. The simulation results show that the new model provides improved predictions of the experimental data.