Flow simulation around double cylinders based on Lattice Boltzmann method at low Reynolds numbers

ABSTRACT

Air filters with low pressure drop and high efficiency are critical for the performance of industrial ventilation system. In order to manufacture air filters with optimal structure, study on flow field characteristic inside the fibrous media is essential. The flow around single cylinder and double cylinders by Lattice Boltzmann method was simulated at low Reynolds number (Re ≤ 1). Results showed that the degree of interference differs with different clearance ratios and arrangements. For serial cylinders, the drag coefficient of the downstream cylinder is less than the upstream, but the change amplitude is greater. The wake effect of upstream cylinder disturbs the downstream cylinder, which has the largest impact when 5 ≤ L/D ≤ 7. The value of C_d/C_d* for parallel cylinders increases with the clearance ratio. The greater the Re value is, the larger the value of C_d/C_d* will be. This study provides an optimal manufacturing direction of fibrous media for good indoor air quality.

KEYWORDS:

• Lattice Boltzmann method
• low Reynolds number
• configuration method
• clearance ratio
• drag coefficient

Acknowledgments

This work is financially supported by the National Natural Science Foundation of China (No.51508267), the Natural Science Foundation of Jiangsu Province (No.BK20130946), the Scientific Research Foundation from Nanjing Tech University (No.39114111) and partially supported by the Qing Lan Project of Jiangsu Province. Acknowledgement is also sent to reviewers for their constructive suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

National Natural Science Foundation of China [grant number 51508267]; Natural Science Foundation of Jiangsu Province [grant number BK20130946]; Scientific Research Foundation from Nanjing Tech University [grant number 39114111]; Qing Lan Project of Jiangsu Province.

Notes on contributors

Bin Zhou

Bin Zhou is an associate professor at Nanjing Tech University, China. He is currently the deputy head for Department of HVAC at College of Urban Construction. His research interests include air filtration, cleanroom technology, micro-contamination control and indoor air quality. He is a member of Chinese Society of Particuology and Chinese Society for Environmental Sciences.

Jiaqi Fan

Jiaqi Fan is a master from Nanjing Tech University, China. She is interested in numerical simulation with particle-laden flow and building energy-saving performance.

Lu Feng

Lu Feng is a master candidate at Nanjing Tech University, China. He is interested in the study of indoor air quality with air filters.

Da Gong

Da Gong is a master from Nanjing Tech University, China. He is skilled at experiment and simulation of building energy consumption and he is familiar with LBM code.

Jianjie Cheng

Jianjie Cheng is an associate professor at Nanjing Tech University, China. She is the head for Department of HVAC at College of Urban Construction. Her research area covers the environmental control in building and energy efficient measures for sustainable development of green buildings.

Liping Chen

Liping Chen is a full professor at Nanjing Tech University, China. She is active in the research field of green building, indoor air quality and pollution control for indoor and outdoor air.