摘要
To improve the efficiency of a CycloBio fluidized sand bed(CB FSB) in removal of dissolved wastes in recirculating aquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics(CFD) modeling tools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simulations with the granular Eulerian multiphase approach and the RNG k-ε turbulence model, and the simulation results were validated using available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numerical simulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model and the Syamlal-O'Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume fraction of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in order to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with the experimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flow in CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.
To improve the efficiency of a CycloBio fluidized sand bed （CB FSB） in removal of dissolved wastes in recirculatingaquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics （CFD） modelingtools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simula-tions with the granular Eulerian multiphase approach and the RNG k-e turbulence model, and the simulation results were validatedusing available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numericalsimulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model andthe Syamlal-O＇Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume frac-tion of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in or-der to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with theexperimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flowin CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.
基金
supported by the 12th Five-year National Technology Support Project(2011BAD13B04)
