Flow Characteristics in a Honeycomb Structure to Design Nanobubble Generating Apparatus. Issue 6 (12th February 2020)

• Record Type: Journal Article
• Authors: Noda, Nao-Aki; Zhai, Hongfang; Takata, Kakeru; Sano, Yoshikazu; Takase, Yasushi; Ren, Fei; Kawano, Ryo; Umekaga, Toshihiko; Yonezawa, Yuji; Tanaka, Hiroyuki
• Other Names: Flood Adrian guestEditor.
• Is Part Of: Chemical engineering & technology. Volume 43:Issue 6(2020)
• Page Start: 1176
• Page End: 1185
• Publication Date: 2020-02-12
• Subjects: Computational fluid dynamics -- Honeycomb structure -- Nanobubbles -- Population balance method; Chemical engineering -- Periodicals; Chemical processes -- Periodicals; 660.05
• DOI: 10.1002/ceat.201900437
• Languages: English
• ISSNs: 0930-7516

Abstract

Abstract: A nanobubble generator with honeycomb structures producing a large amount of water including large nanobubble density in a short time is described. The nanobubble‐generating performance is investigated for large and small apparatus having different honeycomb cell dimensions by applying computational fluid dynamics (CFD) coupled with a population balance model (PBM). The CFD simulation shows that a significant pressure drop and shear stress occur in the bubbly flow in the honeycomb cell. The numerical model is based on the Eulerian multiphase model and the PBM is used to calculate the bubble size distribution. The obtained CFD‐PBM results are compared with the experimental results for large and small apparatus. Bubble size distributions in the honeycomb structure under different inlet absolute pressure can be predicted by the PBM. The maximum shear stress is determined as the main controlling factor for nanobubble generation. Abstract : The mechanism of nanobubble generation and generation ability are studied for a small and a large apparatus using different honeycomb structures based on the results of experiments and computational fluid dynamics/population balance model analysis. The maximum shear stress appearing repeatedly around honeycomb cell corners controls the nanobubble generation.