Two-way Interactions in Particle-Laden Turbulent Channel Flow: Results from Particle-Resolved Simulations


Modulation of the carrier phase turbulence by finite-size inertial particles is relevant to many industrial (e.g., particle transport in pipeline and drag reduction) and environmental applications (e.g., effect of sea-spray droplets on hurricane development). The nature and level of modulation depend on many factors including scales and geometric configurations of the carrier phase flow and particle characteristics such as size, density, mass loading. Finite-size particles may introduce both local viscous dissipation and kinetic energy production.

In this talk, I will discuss our on-going work to develop a particle-resolved simulation of wall-bounded, turbulent particle-laden flow using the mesoscopic lattice Boltzmann (LB) approach. The talk consists of two parts. The first part concerns implementation details, specifically, the treatments at the fluid-moving particle interfaces within the LB approach and careful validation of the approach. In the second part, we study flow modulation by finite-size particles in a particle-laden turbulent channel flow. Results of single-phase turbulent channel flows are first compared to published benchmark DNS results to validate the lattice Boltzmann approach. In this talk, particles are assumed to have a same density as the fluid, and two different particle sizes of the order 10 to 20 wall units are considered. The relative changes due to the presence of solid particles, of the mean flow velocity and rms velocity fluctuations are compared to results from a finite-difference direct forcing (i.e., macroscopic) approach. Phase-partitioned statistics are compared to reveal some local dynamics within each phase. The particle concentration distribution across the channel shows that there is a dynamic equilibrium location resembling the Segre-Silberberg effect known for a laminar wall-bounded flow.

Jan 27, 2015 3:30 PM — 4:30 PM
Bechtel Collaboratory, Discovery Learning Center
Engineering Center, University of Colorado at Boulder, Boulder, CO 80309

University of Delaware