水动力空化是一种很有前途的污水处理方法和技术,而基于空化反应器优化空化产率和性能的设计原理仍然缺乏。计算流体动力学(CFD)实验优化的补充,已经成为解决这个问题的重要工具,由于投资和运营成本低的优点。然而,具有非工程背景或很少CFD基础的研究人员使用简单的数值策略来处理空化流,这可能会导致许多误解,从而导致糟糕的计算。本文介绍了水力空化的基本原理以及空化模型在废水处理中的应用。特别是,多相流模拟的数学模型,包括湍流封闭和空化模型,全面描述,同时还确定和讨论了每个模型的优点和缺点。CFD技术耦合的实例和方法,通过实验观察来研究具有线性和旋流的空化装置的水动力行为,也是批判性总结。建模问题,仍然没有解决,即,数值模型的实施策略,并对空化数的定义进行了识别和讨论。最后,讨论了CFD建模的优势,并概述了CFD在该研究领域的应用前景。期望本文能够为CFD初学者提供决策支持,以有效地进行CFD建模,并促进反应器空化模拟在污水处理领域的发展。
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.