CFD-assisted modeling of the hydrodynamic cavitation reactors for wastewater treatment — A review. (1st November 2022)

• Record Type: Journal Article
• Authors: Hong, Feng; Tian, Hailin; Yuan, Xi; Liu, Shuchang; Peng, Qintian; Shi, Yan; Jin, Lei; Ye, Liqun; Jia, Jinping; Ying, Diwen; Ramsey, Thomas Stephen; Huang, Yingping
• Is Part Of: Journal of environmental management. Volume 321(2022)
• Publication Date: 2022-11-01
• Subjects: Cavitational reactors -- CFD -- Hydrodynamic cavitation -- Mathematical models -- Wastewater treatment; CFD Computational fluid dynamics -- MBR Membrane bioreactor -- AOP Advanced oxidation process -- RSM Response surface methodology, Reynolds stress model -- NCG Non-condensable gas -- RANS Reynolds-averaged Navier-Stokes -- SST Shear-Stress Transport -- CGU Cavitation generation unit -- ARHCR Hydrodynamic cavitation reactor -- DCM Density-correction model -- FBM Filter-based model -- FBDCM Filter-based-density-correction method -- 3D Three-dimensional -- DBM Discrete bubble model -- PBM Population balance model -- TEM Transport equation-based cavitation model -- VOF Volume of fluid -- DES Detached-eddy simulation -- LES Large-eddy simulation -- CER Cavitation efficacy ratio; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.115982
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Hydrodynamic cavitation has been a promising method and technology in wastewater treatment, while the principles based on the design of cavitational reactors to optimize cavitation yield and performance remains lacking. Computational fluid dynamics (CFD), a supplementation of experimental optimization, has become an essential tool for this issue, owing to the merits of low investment and operating costs. Nevertheless, researchers with a non-engineering background or few CFD fundamentals used straightforward numerical strategies to treat cavitating flows, and this might result in many misinterpretations and consequently poor computations. This review paper presents the rationale behind hydrodynamic cavitation and application of cavitation modeling specific to the reactors in wastewater treatment. In particular, the mathematical models of multiphase flow simulation, including turbulence closures and cavitation models, are comprehensively described, whilst the advantages and shortcomings of each model are also identified and discussed. Examples and methods of the coupling of CFD technology, with experimental observations to investigate into the hydrodynamic behavior of cavitating devices that feature linear and swirling flows, are also critically summarized. Modeling issues, which remain unaddressed, i.e., the implementation strategies of numerical models, and the definition of cavitation numbers are identified and discussed. Finally, the advantages of CFD modeling are discussed and the future of CFD applications in this research area is also outlined. It is expected that the present paper would provide decision-making support for CFD beginners to efficiently perform CFD modeling and promote the advancement of cavitation simulation of reactors in the field of wastewater treatment. Highlights: Computational models applied in reactors for wastewater treatment were summarized. Numerical simulations contribute to the research of cavitational reactors. Numerical research into rotating cavitational reactors needs advanced strategies. A new parameter based on the flow is suggested for the study of cavitation yields.