Numerical Simulation of Gas-Particle Two-Phase Flow Characteristic During Deep Bed Filtration Process

A 2-D gas-particle two-phase flow model has been developed to study the flow characteristics in a single channel of a honeycomb ceramic diesel particulate filter. A particle source in cell (PSIC) algorithm is used to calculate the gas-particle two-phase flow. Firstly, the gas-phase flow field alone (without taking into account of the particle-phase) is solved for estimation of gas velocity and pressure fields in the Euler coordinate. Secondly, the particle-phase is added in and particles tracked down in the Lagrange coordinate. Thirdly, the particle source which acts on the gas-phase cell is calculated and added to the gas-phase equations. Fourthly, the gas-phase equations with the particle source are solved again. Lastly, the above process is iterated until the flow field is convergent.

Taking the above-mentioned approach, the gas-particle two-phase flow characteristic is simulated using FLUENT. The simulation results are in good agreement with experiment data. After the models being calibrated, the influences on particle movement traces of the exhaust gas entry velocity, particulate matter concentration and porous wall thickness are studied and presented.

The work conducted provides an important reference to further studies on gas-particle two-phase flow and combustion characteristics during the cake filtration process and the regeneration process.