Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines
This study employs both experimental and numerical simulation methods to systematically investigate the influence of sudden expansion diameter ratios on methane–air premixed flame propagation, explosion overpressure, and the evolution of turbulent structures. The results show that with the increase...
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2025-03-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/18/5/1301 |
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| author | Ning Zhou Zhuohan Shi Xue Li Bing Chen Yiting Liang Zhaoyu Li Chunhai Yang Xuanya Liu Weiqiu Huang Xiongjun Yuan |
| author_facet | Ning Zhou Zhuohan Shi Xue Li Bing Chen Yiting Liang Zhaoyu Li Chunhai Yang Xuanya Liu Weiqiu Huang Xiongjun Yuan |
| author_sort | Ning Zhou |
| collection | DOAJ |
| description | This study employs both experimental and numerical simulation methods to systematically investigate the influence of sudden expansion diameter ratios on methane–air premixed flame propagation, explosion overpressure, and the evolution of turbulent structures. The results show that with the increase in the diameter ratio, the flame propagation velocity and explosion overpressure present a nonlinear trend of first increasing, then decreasing, and then increasing. Specifically, when the diameter ratio is 1.5, an optimal balance between turbulence enhancement and energy dissipation is achieved, and the overpressure attenuation rate is 47.61%. However, when the diameter ratio increases to 2.0, the turbulence intensity significantly escalates, the peak flame propagation speed increases by 81%, the peak explosion overpressure increases by 69%, and the overpressure attenuation efficiency decreases, which brings greater safety challenges. Moreover, when the diameter ratio is between 1.5 and 2.0, the turbulence intensity of the premixed gas explosion flow field is significantly increased, and the stable “tulip flame” propagation velocity range is extended from 16~35 m/s to 16~42 m/s. When the diameter ratio is 2.0, a distinctive four-vortex structure is formed, with strong turbulent mixing and fast energy dissipation. The vortex structure evolves with the diameter ratio, transitioning from a symmetric and stable double-vortex form to a complex multi-vortex system. The research results provide theoretical support for the prevention of explosions. |
| format | Article |
| id | doaj-art-9bef0b1436184cd48de2def2145dd48c |
| institution | OA Journals |
| issn | 1996-1073 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj-art-9bef0b1436184cd48de2def2145dd48c2025-08-20T02:04:36ZengMDPI AGEnergies1996-10732025-03-01185130110.3390/en18051301Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion PipelinesNing Zhou0Zhuohan Shi1Xue Li2Bing Chen3Yiting Liang4Zhaoyu Li5Chunhai Yang6Xuanya Liu7Weiqiu Huang8Xiongjun Yuan9School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou 213164, ChinaSchool of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou 213164, ChinaSchool of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou 213164, ChinaInstitute of Industrial Safety, China Academy of Safety Science and Technology, Beijing 100012, ChinaSchool of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou 213164, ChinaSchool of Overseas Education, Changzhou University, Changzhou 213164, ChinaSchool of Materials Engineering, Changshu Institute of Technology, Suzhou 215500, ChinaTianjin Fire Research Institute of MEM, Tianjin 300381, ChinaSchool of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou 213164, ChinaSchool of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou 213164, ChinaThis study employs both experimental and numerical simulation methods to systematically investigate the influence of sudden expansion diameter ratios on methane–air premixed flame propagation, explosion overpressure, and the evolution of turbulent structures. The results show that with the increase in the diameter ratio, the flame propagation velocity and explosion overpressure present a nonlinear trend of first increasing, then decreasing, and then increasing. Specifically, when the diameter ratio is 1.5, an optimal balance between turbulence enhancement and energy dissipation is achieved, and the overpressure attenuation rate is 47.61%. However, when the diameter ratio increases to 2.0, the turbulence intensity significantly escalates, the peak flame propagation speed increases by 81%, the peak explosion overpressure increases by 69%, and the overpressure attenuation efficiency decreases, which brings greater safety challenges. Moreover, when the diameter ratio is between 1.5 and 2.0, the turbulence intensity of the premixed gas explosion flow field is significantly increased, and the stable “tulip flame” propagation velocity range is extended from 16~35 m/s to 16~42 m/s. When the diameter ratio is 2.0, a distinctive four-vortex structure is formed, with strong turbulent mixing and fast energy dissipation. The vortex structure evolves with the diameter ratio, transitioning from a symmetric and stable double-vortex form to a complex multi-vortex system. The research results provide theoretical support for the prevention of explosions.https://www.mdpi.com/1996-1073/18/5/1301sudden expansion structurediameter ratioflame structurepeak overpressurevortex structure |
| spellingShingle | Ning Zhou Zhuohan Shi Xue Li Bing Chen Yiting Liang Zhaoyu Li Chunhai Yang Xuanya Liu Weiqiu Huang Xiongjun Yuan Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines Energies sudden expansion structure diameter ratio flame structure peak overpressure vortex structure |
| title | Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines |
| title_full | Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines |
| title_fullStr | Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines |
| title_full_unstemmed | Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines |
| title_short | Study on the Deflagration Characteristics of Methane–Air Premixed Gas in Sudden Expansion Pipelines |
| title_sort | study on the deflagration characteristics of methane air premixed gas in sudden expansion pipelines |
| topic | sudden expansion structure diameter ratio flame structure peak overpressure vortex structure |
| url | https://www.mdpi.com/1996-1073/18/5/1301 |
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