2014/11/05 by Sunil K. Arolla, Arolla, Sunil K., Olivier Desjardins +1
Engineering · Environmental Science · #Granular flow and fluidized beds #Hydrology and Sediment Transport Processes #Particle Dynamics in Fluid Flows
paper · pdf · doi:10.48550/arxiv.1411.1475
A volume-filtered Euler-Lagrange large eddy simulation methodology is used to\npredict the physics of turbulent liquid-solid slurry flow through a horizontal\npipe. A dynamic Smagorinsky model based on Lagrangian averaging is employed to\naccount for the sub-filter scale effects in the liquid phase. A fully\nconservative immersed boundary method is used to account for the pipe geometry\non a uniform cartesian grid. The liquid and solid phases are coupled through\nvolume fraction and momentum exchange terms. Particle-particle and\nparticle-wall collisions are modeled using a soft-sphere approach. A series of\nsimulations have been performed by varying the superficial liquid velocity to\nbe consistent with the experimental data by Dahl et al. (2003). Depending on\nthe liquid flow rate, a particle bed can form and develop different patterns,\nwhich are discussed in the light of regime diagrams proposed in the literature.\nThe fluctuation in the height of the liquid-bed interface is characterized to\nunderstand the space and time evolution of these patterns. Statistics of\nengineering interest such as mean velocity, mean concentration, and mean\nstreamwise pressure gradient driving the flow are extracted from the numerical\nsimulations and presented. Sand hold-up calculated from the simulation results\nsuggest that this computational strategy is capable of accurately predicting\ncritical deposition velocity.\n