Abstract
We study dynamic flow-structuring and mean-flow properties of turbulent particle-laden riser-flow at significant particle volume fractions of about 1.5%. We include particle–particle as well as particle–fluid interactions through inelastic collisions and drag forces, in a so-called four-way coupled description. These interactions are the origin for the emergence of coherent particle swarms in a flow. The dynamic cluster-formation and cluster-disintegration are associated with the competition between turbulent dispersion and inelastic particle collisions. We establish the basic scenario of this self-organization and investigate the dominant mean-flow aspects of the resulting turbulence modulation for particles with high Stokes response-time. Large-eddy simulations of turbulent channel flow, using dynamic subgrid models and particles at a significant volume fraction and realistic mass load are presented. These simulations indicate the development of a thinner boundary layer, a flatter velocity profile, an higher effective Von Kármán constant and an accumulation of particles near the walls. Moreover, it was found that neglecting particle–particle interactions, as done in so-called two-way coupling, leads to a modulated flow which displays a strong ‘center-channel-jet’ that is not found in physical experiments.
Original language | Undefined |
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Article number | 10.1016/j.ijheatfluidflow.2006.03.025 |
Pages (from-to) | 945-954 |
Number of pages | 10 |
Journal | International journal of heat and fluid flow |
Volume | 27 |
Issue number | 11/5 |
DOIs | |
Publication status | Published - Oct 2006 |
Event | The 6th International Symposium on Engineering Turbulence Modelling and Measurements - ETMM6 - Duration: 1 Oct 2006 → 1 Oct 2006 |
Keywords
- Turbulence
- Turbulence modulation
- Large eddy simulation
- Particle laden flow
- EWI-9007
- Inelastic collisions
- IR-63901
- Channel flow
- Coherent structures
- Four-way coupling
- METIS-237898