Practical validation of the two-fluid model applied to dense gas-solid flows in fluidized beds |
| |
Authors: | HÅ vard Lindborg,Hugo A. Jakobsen |
| |
Affiliation: | a Department of Chemical Engineering, Norwegian University of Science and Technology, NTNU, Sem Sælands vei 4, No-7491 Trondheim, Norway b Department of Process Technology, SINTEF, No-7034 Trondheim, Norway |
| |
Abstract: | This paper discusses the simulation of bubbling gas-solid flows by using the Eulerian two-fluid approach. Predictions of particle motion, bed expansion, bubble size and bubble velocity in bubbling beds containing Geldart B particles are compared with experimental results and correlations found in the literature. In addition, gas mixing in a bed of Geldart A particles is investigated.An in-house code has been developed based on the finite-volume method and the time-splitting approach using a staggered grid arrangement. The velocities in both phases are obtained by solving the 2D Reynolds-averaged Navier/Stokes equations using a partial elimination algorithm (PEA) and a coupled solver. The k-ε turbulence model is used to describe the turbulent quantities in the continuous phase.In general, the model predictions are in good agreement with experimental data found in the literature. Most important observations are: the level of the restitution coefficient was found to be crucial in order to obtain successful results from 2D axisymmetric simulations of a system containing Geldart B particles. Bubble size and bubble rise velocities are not as sensitive to the restitution coefficient. The turbulence model is of outmost importance concerning gas mixing in a fluidized bed of Geldart A particles.From these numerical analyzes an optimized granular flow two-fluid model can be designed for the purpose of simulating reactive systems in fluidized bed reactors. |
| |
Keywords: | Fluid mechanics Fluidization Granular materials Multiphase flow Simulation Turbulence |
本文献已被 ScienceDirect 等数据库收录! |
|