Simulations are presented for complex recirculating particle-laden flows in the two-way coupling regime using a probability density function form of the population balance equation (PDF-PBE). Large eddy simulation is employed for the carrier fluid whereas a stochastic version of the PDF-PBE is adopted for the dispersed phase. The present work focuses on the particle dispersion while other physics such as particle-particle interactions are neglected. The method of Stokes binning is used to explicitly treat effects of inertia. The model is implemented into a well-known open source computational fluid dynamics (CFD)code known as OpenFOAM. The results are compared with the experiment of Borée et al. (2001)which studied the injection of 20–100 µm beads into a bluff body configuration at a mass loading of 22% where the impact of dispersed elements on the carrier phase is important. The PDF-PBE method produces high-quality results compared to the measurements. The results demonstrate that the stagnation points and carrier phase velocity profiles are captured very well although the velocity RMS values are slightly over predicted. The agreement between the PDF-PBE and the measurements are also very good for both particle velocity and dispersion, however some discrepancies are observed for smaller particles. To investigate the effect of momentum coupling, the simulations are repeated using only one-way coupling. It is found that the impact of momentum coupling is important, in particular in modifying the recirculation region. The results show that the difference between one-way and two-way coupled simulations are greatest for smaller particles due to the strong effect of the carrier phase while this difference is much smaller for larger particles since they are less affected by changes in the carrier phase.
|Number of pages||11|
|Journal||International Journal of Multiphase Flow|
|Publication status||Published - Aug 2019|
- Large eddy simulation
- Population balance equation
- Stochastic lagrangian
- Bluff body