AIChE Journal, Vol.41, No.10, 2187-2197, 1995
Numerical Computation of Turbulent Gas-Solid Particle Flow in a 90-Degrees Bend
A numerical computation of the LDV results of Kliafas and Holt is reported for a turbulent gas-solid particle flow in a square-sectioned 90 degrees bend. A Eulerian model with generalized Eulerian solid surface boundary conditions for the particulate phase is employed. In the momentum balance equation, the particulate-phase momentum exchanges with solid walls are included. The turbulent closure is effected by using the gas-phase RNG-based k-epsilon turbulence model and the particulate turbulence diffusivity is related to the turbulent viscosity of the gas phase. Comparisons are made with experimental data for the mean streamwise velocities of both phases, the streamwise turbulence intensity of the gas phase, and the particulate concentration distribution in the bend. The localized high particulate concentration near the outer curve of the bend that occurs at large Stokes number is accurately predicted. Empirical computational evidence is presented for a relaxation of the minimum particle number density required to allow the use of a continuum model.