Sensitivity analysis of grid size for bubble flow field analysis using image analysis methods

Sung Jung Kim; Chang-Lae Jang

doi:10.3741/JKWRA.2024.57.8.549

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2024 Vol.57, Issue 8 Preview Page Next Page

Research Article

Sensitivity analysis of grid size for bubble flow field analysis using image analysis methods 영상분석기법 기반 기포유동장 해석을 위한 격자의 민감도 분석

31 August 2024. pp. 549-559

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Abstract

This study aims to investigate the feasibility of using image analysis methods to examine the flow characteristics of air bubbles discharged underwater. A bubble screen was created using multiple nozzles in a laboratory flume filled with stagnant water. The flow characteristics of the bubbles were analyzed, and the suitability of the analysis method was evaluated. Several parameters, such as projection area ratio and depth ratio, were defined to conduct laboratory experiments and analyze the flow characteristics of the bubbles. Correlation and regression analyses were performed to assess the relationships between various variables. Specifically, the correlation between the bubble's projection area and its rising speed across eight water depth ratios was examined. The results indicated that as the depth ratio increased, the bubble size exhibited a linear increase with a strong correlation as it rose to the water surface due to pressure effects. Regarding the sensitivity of different grid sizes in the ten analysis grids when applying image analysis methods, it was observed that the sensitivity to grid size based on the projection area ratio (0.09~0.96) was not significant. These findings suggest that image analysis techniques can be effectively utilized to observe the flow characteristics of bubbles.

Keywords

Image analysis

Air bubble

Grid size

Bubble size

Rising velocity

본 연구에서는 수중에서 방출되는 기포의 유동특성 분석 및 거동을 해석을 위해 이용하는 영상분석기법의 적용성을 검토하기 위하여 실내실험을 수행하고 기포유동장 해석을 위한 격자의 민감도 분석을 하였다. 실내실험 수로 내에 정지유체 상태에서 여러 개의 노즐을 이용하여 기포를 발생시켜 기포장벽을 만들고 유동특성을 검토함으로써 분석방법의 적절성과 해석격자의 민감도를 분석하였다. 수리실험을 통한 기포의 유동특성을 분석하기 위해 해석격자에 대한 기포의 평균투영면적의 비인 투영면적비, 해석영역의 중심부 수심과 총수심과의 비인 수심비 등 매개변수를 정의하고, 각각의 변수간의 관계를 파악하기 위하여 상관분석 및 회귀분석을 수행하였다. 8가지 수심비에 따른 기포투영면적, 기포상승속도와의 관계를 분석한 결과, 수심비가 증가할수록 압력의 영향으로 인해 수면으로 상승할수록 기포의 크기는 높은 상관성을 가지며 선형적으로 증가하였다. 영상분석기법 적용을 위한 8가지 해석격자의 크기별 민감도 영향에서 투영면적비(0.09~0.96)에 따른 격자크기에 대한 민감도는 크지 않은 것으로 확인되었다. 이러한 결과를 통해 영상분석기법이 기포의 유동특성을 관측할 수 있는 적절한 기법이 될 수 있을 것으로 판단된다.

키워드

이미지분석

기포

격자크기

기포크기

상승속도

References

An, K.S., Jeon. H.S., and Park. C.H. (2020). "Measurement of bubble size in flotation column using image analysis system." Journal of Korean Inst. of Resources Recycling, Vol. 29, No. 6, pp. 104-113.

10.7844/kirr.2020.29.6.104

Bacot, A., Frank, D., and Linden, P. (2022). "Bubble curtains used as barriers across horizontal density stratifications." Journal of Fluid Mechanics, Vol. 941, No. A1. pp. 1-41.

10.1017/jfm.2022.142

Cheng, W., Murai, Y., Sasaki, T., and Yamamoto, F. (2005) "Bubble velocity measurement with a recursive cross correlation PIV technique." Flow Measurement and Instrumentation, Vol. 16, No. 1, pp. 35-46,

10.1016/j.flowmeasinst.2004.08.002

Cîrciumaru, G., Chihaia, R.A., Voina, A., Gogoașe Nistoran D.E., Simionescu Ș.M., El-Leathey, L.A., Mândrea, L. (2022). "Experimental analysis of a fish guidance system for a river water intake." Water, Vol. 14. No. 3, pp. 1-22.

10.3390/w14030370

Jang, H.J., Lee, H.S., Lee, H.J., and Kim, B.K. (2017). "A basic experimental analysis of air bubble barrier." Crisisonomy, Vol. 13, No. 8, pp. 61-68.

10.14251/crisisonomy.2017.13.8.61

Kim, S.M., Yi, S.J., Kim, H.D., Kim, J.W., and Kim, K.C. (2010). "Dynamic analysis of bubble-driven liquid flows in a rectangular tank." Journal of the Korean Society of Visualization, Vol. 8, No. 1, pp. 31-38.

10.5407/JKSV.2010.8.1.031

Liu, Z., and Zheng, Y. (2006). "PIV study of bubble rising behavior." Powder Technology, Vol. 168, No. 1, pp. 10-20.

10.1016/j.powtec.2006.05.020

Lo, J.M. (1991). "Air-bubble barrier effects on neutrally buoyant objects." Journal of Hydraulic Research, Vol. 29, No. 4, pp. 437-455.

10.1080/00221689109498967

Lo, J.M. (1997). "The effect of air-bubble barriers in containing oil-slick movement." Ocean Engineering, Vol. 24, No. 7, pp. 645-663.

10.1016/S0029-8018(96)00037-6

Murgan, I., Bunea, F., and Ciocan, G.D. (2017). "Experimental PIV and LIF characterization of a bubble column flow." Flow Measurement and Instrumentation, Vol 54, pp 224-235.

10.1016/j.flowmeasinst.2017.02.004

Muste, M. Hauet, A., Fujita, I., Legout, C., and Ho, H.-C. (2014). "Capabilities of large-scale particle image velocimetry to characterize shallow free-surface ﬂows." Advances in Water Resources, Vol. 70, pp. 160-170.

10.1016/j.advwatres.2014.04.004

Seo, H.D., Aliyu, M.A., Kim, M.K., and Kim, K.C. (2017). "A study on bubble behavior generated by an air-driven ejector for ABB (Air Bubble Barrier) (I): Development of image processing method and statistical analysis." Journal of the Korean Society of Visualization, Vol. 15, No. 2, pp. 48-58.

Information

Publisher :KOREA WATER RESOURECES ASSOCIATION
Publisher(Ko) :한국수자원학회
Journal Title :Journal of Korea Water Resources Association
Journal Title(Ko) :한국수자원학회 논문집
Volume : 57
No :8
Pages :549-559
Received Date : 2024-03-18
Revised Date : 2024-07-31
Accepted Date : 2024-07-29
DOI :https://doi.org/10.3741/JKWRA.2024.57.8.549

Journal of Korea Water Resources Association ISSN:2799-8746(Print) 2799-8754(Online) 한국수자원학회 논문집

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