A review of multiscale CFD for gas–solid CFB modeling

Wang, Wei; Lu, Bona; Zhang, Nan; Shi, Zhansheng; Li, Jinghai

doi:10.1016/j.ijmultiphaseflow.2009.01.008

Cited by 145 publications

(58 citation statements)

References 31 publications

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“…At present, most of the CFD riser simulations remain limited to calculating the flow in a simplified 2-D riser domain, making it impossible to reconstruct the 3D nature of the flow in the riser. In view of the importance of flow structures, the simplified approach does not allow to determine the real mechanisms underlying the complex state of motion [2]. As a consequence, hydrodynamic modeling of a riser has not yet been entirely successful [1].…”

Section: Introductionmentioning

confidence: 99%

Three-component solids velocity measurements in the middle section of a riser

Pantzali

Bayon

Heynderickx

et al. 2013

Chemical Engineering Science

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Coincident three-component experiments are conducted in a 8.7-m-high cylindrical riser (internal diameter 0.10 m) of a Pilot-Scale Cold-Flow Circulating Fluidized Bed set-up using two LDA probes. At heights close to the solids inlet, the flow is highly disturbed due to the asymmetrical position of both the air and solids inlets. A fully developed parabolic axial solids velocity field is observed at a height of 2.5 m. The radial and azimuthal solids velocity components are significantly smaller than the axial one and are close to zero. The velocity fluctuations in the flow direction are larger than in the other directions, showing that the flow is anisotropic. However, the radial and azimuthal velocity fluctuations are higher than the corresponding mean velocities. All fluctuating velocities are decreasing significantly with increasing riser height, i.e. as the flow becomes more developed. No average down-flow of solids is recorded, not even close to the wall, probably due to the very high dilution (ε s <0.2%) used in the presented work. The measured turbulent kinetic energy indicates that the flow is dominated by wall-particle rather than intra-particle collisions. The acquired data can be useful for validation of riser simulations.

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Section: Introductionmentioning

confidence: 99%

Three-component solids velocity measurements in the middle section of a riser

Pantzali

Bayon

Heynderickx

et al. 2013

Chemical Engineering Science

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“…Until now, the fact that acceptable general theory is not yet developed for all flow conditions heavily affects its application. Moreover, it was found that the TFM may overestimate the drag coefficient without sub-grid structures treatment (Wang, et al, 2010) for common grid methods.…”

Section: Numerical Simulation Of a Self-leveling Experiments Using A Hmentioning

confidence: 99%

Numerical simulation of a self-leveling experiment using a hybrid method

Guo

Morita

Tagami

et al. 2014

Mechanical Engineering Journal

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The postulated core disruptive accidents (CDAs) are regarded as particular difficulties in the safety analysis of liquid-metal fast reactors (LMFRs). In the CDAs, the self-leveling behavior of debris bed is a crucial issue, which greatly affects the relocation process and heat-removal capability of molten core. SIMMER-III is a fast reactor safety analysis code and successfully applied to a series of the CDA assessments. It is a 2D, multi-velocity-field, multiphase, multicomponent, Eulerian, fluid dynamics code coupled with a fuel-pin model and a space-and energy-dependent neutron kinetics model. However, strong interactions between solid particles, as well as particle characteristics, in multiphase flows with particles are not taken into consideration in SIMMER-III. In this article, a hybrid method is developed by coupling the discrete element method (DEM) with the multi-fluid model of SIMMER-III, and the numerical simulation of a simplified self-leveling experiment is presented. In the coupling algorithm, the governing equations of gas and liquid phases are solved by a time-factorization (time-splitting) method. Contact forces between particles and interactions between particles and fluid are considered in the DEM. Reasonable agreement between simulation results and corresponding experimental data can demonstrate the validity of the present method in simulating the self-leveling behavior of debris bed.

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“…With the development of hydrodynamic modeling for the gase solid flow, the numerical simulation for the flow character has become an important and effective method for the CFBs' research [16]. There are two different approaches might be used to simulate the gasesolid flow, namely the Lagrangian and the Eulerian methods.…”

Section: Introductionmentioning

confidence: 99%