| 张宁，张帆，钟生辉，于江飞，彭志军，刘海峰.乙醇预混火焰胞状不稳定性的数值模拟和理论研究[J].内燃机工程,2020,41(2):25-31. |
| Numerical and Theoretical Investigation of Cellular Instability of Premixed Ethanol/Air Flames |
| DOI：10.13949/j.cnki.nrjgc.2020.02.004 |
| Key Words:ethanol hydrodynamic instability thermal-diffusion instability numerical simulation internal combustion engine |
| Author Name | Affiliation | | ZHANG Ning,ZHANG Fan,ZHONG Shenghui,YU Jiangfei,PENG Zhijun,LIU Haifeng | 1.State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China；
2.Science and Technology on Scramjet Laboratory, National University of Defense Technology, Changsha 410073, China |
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| 摘要点击次数: 3537 |
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| Abstract:A series of numerical simulations of premixed cylindrical expanding ethanol/air flames in a constant volume were performed to investigate the cellular instability. Then a theoretical analysis in terms of critical Peclet number, logarithmic growth rate and critical flame radius was carried out to explore the flame instability. The results demonstrate that at pressure of 1 MPa and temperature of 358 K, ethanol/air flame cellular instability increases non-monotonically with the equivalence ratio changing from 0.8 to 1.6 and has the most intense instability when the equivalence ratio is 1.2. It is found that thermal-diffusion instability changes dramatically with increased equivalence ratio mainly due to molecular diffusion, and logarithm growth rate increases first and then decreases. On the contrary, hydrodynamic instability is insensitive to the equivalence ratio. Finally, the almost constant critical Peclet number and remarkably reduced flame thickness lead to a great decrease in critical flame radius when the equivalence ratio is less than 1.2, and critical flame radius reaches the minimum when the equivalence ratio is 1.2. Both numerical and theoretical investigations showed a consistent result. |
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