COMPARISON BETWEEN TWO-FLUID MODEL PREDICTIONS AND LARGE EDDY SIMULATION RESULTS IN A VERTICAL GAS-SOLID TURBULENT CHANNEL FLOW

摘要

This paper concerns the numerical prediction of gas-solidrnturbulent channel flows using a continuum approach for therndispersed phases. A model, based on separate transport equationsrnfor the components of the particle kinetic stress tensor, isrnbriefly presented and the corresponding predictions are comparedrnwith large eddy simulation (LES) results. In the LESrncalculations, particle motion is governed only by drag and thernvolume fraction of the dispersed phase is assumed to be smallrnenough such that particle-particle collisions and fluid turbulencernmodulation are negligible. It is shown that the particle kineticrnstress transport model gives a satisfactory description for thernmechanisms governing the particle velocity fluctuation in thernflow: production of the streamwise particle velocity fluctuationsrnby the mean velocity gradient, production of the wall-normalrnand spanwise velocity fluctuations by the fluid-particle velocityrncorrelations and turbulent transport by the third order particlernvelocity correlations.