Co-simulating fouling, erosion of gas-particle flow and morphologies predictions around circular tube via parallel CFD-DEM modeling

摘要

In this paper, a novel CFD-DEM model, co-simulating erosion, fouling of the gas-particle flow and predicting morphologies, is presented to simulate the industrial circular tube. The particle impact model is treated as a mechanistic foundation to build particle sticking and erosion sub-models, which is more convenient to assess the fouling state and the erosion rate. Morphologies for particle fouling and erosion are given by the clustered particles and the dynamic mesh. Most innovative in the particle fouling, converting the DEM particle parcel into the particle container is used to the fouling time magnification, which has been testified reasonable. Results indicate that the proposed model can be used for co-simulating erosion, fouling of gas-particle flow and morphologies predictions when validated by experimental data. For fouling, the fouling layer prevents the particle to impact the tube wall and itself, resulting in the decline of impaction efficiency and the slow change of fouling. The mass deposition of low-velocity fine particle is still massive, despite that the impaction efficiency is lower. The fouling growth is first quick, and then becomes slow. The fouling process of the fine particle needs more time than the large particle to reach the critical fouling thickness. For erosion, the mass loss presents the linear growth as time goes up. The erosion rate is almost proportional to the 3.4 power of particle size, and the 2.7 power of particle velocity.