888 Google Scholar citations and 100 citations for a paper

888 Google Scholar citations and 100 citations for a paper

Recently published papers:

Y. L. Wu, Q. F. Hou, A. B. Yu. Linking discrete particle simulation to continuum properties of the gas fluidization of cohesive particles. AIChE Journal, In Press (2020).

Abstract

Discrete particle simulation can explicitly consider interparticle forces and obtain microscopic properties of the fluidized cohesive particles, but it is computationally expensive. It is thus pivotal to link the microscopic discrete properties to the macroscopic continuum description of the system for large scale applications. This work studies the fluidization of cohesive particles through the coupled computational fluid dynamics and discrete element method (CFD-DEM). First, discrete CFD-DEM results show the increased particle cohesion leads to the severe particle agglomeration which affects the fluidization quality significantly. Then, continuum properties are attained by a weighted time-volume averaging method, showing that tensile pressure becomes significant as particle cohesion increases. By incorporating the Rumpf correlation into the solid pressure equation, the tensile pressure could be predicted consistently with the averaged CFD-DEM results for different particle cohesion. Finally, those overall steady averaged properties of the bed are obtained for understanding the general macroscopic properties of the system.

Keywords: fluidization, CFD-DEM, averaging method, cohesive particle, agglomeration

Q. F. Hou, D. Y. E, S. B. Kuang, A. B. Yu. A process scaling approach for CFD-DEM modelling of thermochemical behaviours in moving bed reactors. Fuel Processing Technology In Press (2020).

Abstract

Intensive heat and mass transfer between continuum fluids and discrete particulate materials plays a critical role in many chemical reactors. The residence and chemical reactions of particulate materials could span over hours. To understand and improve the operation of these reactors, discrete particle models are very helpful and computationally demanding. Different to the previous coarse grain model in reducing computational cost by reducing total particle number with large representative particles, a scaling approach by changing process parameters and thus the time scale is established to significantly reduce computational cost for the combined computational fluid dynamics (CFD) and discrete element method (DEM) modelling of moving bed reactors. The scaled model is first derived based on the governing equations of mass, momentum and energy for two-phase flow and then applied to a moving bed reactor. The results in terms of flow, heat and mass transfer and chemical reactions with different time scaling factors demonstrate that two-order acceleration in terms of computational time can be achieved while reliably representing the same physical process. The possible use of the scaling approach to other systems is discussed. The scaling approach represents a critical step forward towards establishing virtual real-time thermochemical reactors with discrete particle models.

Keywords: CFD-DEM; Scaling; Heat and mass transfer; Chemical reaction; Moving bed reactor