Phase distribution and velocity field sketch out hydrodynamics characteristics of flat-sheet MBR (membrane bioreactor)

which could be analyzed by multiphase and turbulence models efficiently. Aiming at structure optimization

fouling mitigation and energy reduction for MBR

flat-sheet membranes of three major domestic and abroad companies

including Kubota

Toray and SINAP

were chosen to investigate spatial structure of commercial submerged flat-sheet MBR

and to compare effects of different multiphase and turbulence models on phase distribution

velocity field and computational expense. Results showed that the spatial structure of all three flat-sheet membrane was usually designed according to company's manuals

resulting that ratios of length/width and height/diameter were in the range of 1.37±0.63 and 0.97±0.23

respectively. Multiphase model plays key roles rather than turbulence models in phase distribution and velocity field simulation

and the combination of VOF (volume of fluid) and standard k-ε is more accurate and faster for simulating velocity field of submerged flat-sheet MBR. Multiphase model is the key factor of affecting computational costs. On 6 cores platform

VOF consumes 4.5-2.2 times more CPU time than mixture

and realizable k-ε consumes almost the same time as standard k-ε.