Two‐fluid model for particle‐turbulence interaction in a backward‐facing step

Abstract

in Wiley InterScience (www.interscience.wiley.com).Particle-turbulence interaction for dilute gas-particle flows over a backward-facing step geometry is numerically investigated. An Eulerian two-fluid model with additional turbulence transport equations for particles is employed in this investigation. RNG based k-e model is used as the turbulent closure with additional transport equations solved, to better represent the combined gas-particle interactions. Two different particle classes with same Stokes number and varied particle Reynolds number are considered in this study. The turbulence modulation of the carrier phase in the presence of the dispersed particulate phase is simulated and compared against the experimental data. However prior to this endeavour, the simulated flow field is validated for mean streamwise velocities and fluctuations for both the phases. Despite the fact that the two particles used in this study share the same Stokes number their behavior is found to be considerably different in the turbulent flow field, which basically underlines the fact that the Stokes number alone is not enough to fully describe the behavior of particles, thereby, herein particle Reynolds number is also investigated to fully understand their behavior. Two other turbulence modulation models were also tested against our own formulation, and our model was found to compare better with the experimental findings.

The effect of drop evaporation on gas turbulence and heat transfer for two-phase flow behind sudden pipe expansion

“…The analysis of our calculation data and the experimental data [11] suggests that the effect of the dispersed phase on the change in the averaged gas velocity is insignificant throughout the channel length. Analogous results were obtained in recent numerical works [23][24][25]. The axial gas velocity in the two-phase flow is slightly higher than that in the single-phase flow at y/H > 1.5 in the calculated sections x/H = 9 and 14.…”

Hydrodynamic Modeling of Dense Gas-Particle Turbulence Flows Under Microgravity Space Environments

“…Therefore, it is reasonable that this term will be dealt with a turbulence dissipation term for gas-particle phase. Mohanarangam and Tu (2007) proposed the correlation transportation equation based on the isotropic turbulence kinetic energy (scalar quantity). Only the shortcoming is that the closed transportation equation cannot reflect the anisotropic turbulence flows.…”

Modeling Performance of a Tangential Flow Cyclone: Effects of Secondary Outlet Geometry and Boundary Conditions

“…We employed several RANS equations-based turbulent closure models to calculate the flow field with several tangential flow cyclones, including (i) standard k-e model (Launder and Spalding 1972;Jones et al 1972); (ii) RNG-based k-e model (Yakhot et al 1986;Mohanarangam and Tu 2007) wherein the equation for e includes an extra term to improve the model performance for more complex flows; and (iii) RSM (Launder 1989). Implementation of the latter model requires inter alia calculations by the former two closure schemes.…”

“…Particle transport in turbulent flows is normally treated by Eulerian and Lagrangian models, respectively, viewing particles as a continuum, (second fluid) and as individual objects, each moving along its stochastic trajectory (Crowe, Sommerfeld, and Tsuji 1998;Mohanarangam and Tu 2007). In the Lagrangian approach, particle turbulence is normally investigated by Eddy Interaction Model, where a discrete particle is assumed to interact with a succession of turbulent eddies.…”