Large-eddy simulations of a vertical turbulent channel flow with 420,000 solid particles are performed in order to get insight into fundamental aspects of a riser flow. The question is addressed whether collisions between particles are important for the flow statistics. The turbulent channel flow corresponds to a particle volume fraction of 0.013 and a mass load ratio of 18, values that are relatively high compared to recent literature on large-eddy simulation of two-phase flows. In order to simulate this flow, we present a formulation of the equations for compressible flow in a porous medium including particle forces. These equations are solved with LES using a Taylor approximation of the dynamic subgrid-model. The results show that due to particle-fluid interactions the boundary layer becomes thinner, leading to a higher skin-friction coefficient. Important effects of the particle collisions are also observed, on the mean fluid profile, but even more on particle properties. The collisions cause a less uniform particle concentration and considerably flatten the mean solids velocity profile.
|Publication status||Published - 2010|
|Event||conference; Lecture given at: Contactgroep Turbulentie, TU-Delft; 2010-10-04; 2010-10-04 - |
Duration: 4 Oct 2010 → 4 Oct 2010
|Conference||conference; Lecture given at: Contactgroep Turbulentie, TU-Delft; 2010-10-04; 2010-10-04|
|Period||4/10/10 → 4/10/10|
|Other||Lecture given at: Contactgroep Turbulentie, TU-Delft|