Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube (PDF)
发布时间：2025-04-30
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- 发布时间：
- 2025-04-30
- 论文名称：
- Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube (PDF)
- 发表刊物：
- Chinese Sci Bulletin
- 摘要：
- Ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures with hydrogen fractions from 0% to 20% were measured in a shock tube facility. Ambient temperature varies from 1422 to 1877 K and pressure is kept at 0.4 MPa behind the reflected shock wave. Experiment was conducted at equivalence ratio of 2.0 and nitrogen dilution ratio of 95%. Experimental results show that the ignition delay times of CH4/H2 decreases with the increase of hydrogen fraction. The enhancement on ignition by hydrogen addition becomes small when ambient temperature is over 1750K, and the enhancement effect is strong when temperature is below 1725 K. Ignition delay time of 20%H2/80%CH4 is only one-third to that of 100%CH4 at the temperature of 1500K. A modified model based on GRI-Mech 3.0 is proposed and used to calculate the ignition times of CH4/H2/O2/N2 mixtures. The measured ignition delay times are compared with the calculated values obtained from the modified mechanism, and good agreement between measured and calculated is presented. Analysis on normalized sensitivity indicates that OH+H2=H+H2O is the main reaction for the formation of H radical at temperature of 1400 K. With the increase of hydrogen fraction, chain branching is promoted through H+O2=O+OH, and decreases the ignition delay times. At the temperature of 1800 K, CH3 radical becomes the key species that influences the ignition of CH4/H2/O2/N2 mixtures, and sensitivity coefficients of chain termination reaction 2CH3(+M)=C2H6(+M), and HO2+CH3=OH+CH3O are reduced, lowering the promotion effect from hydrogen addition on ignition of methane/hydrogen mixtures under high temperature.
- 合写作者：
- Zhang YJ, Huang ZH, Wei LJ, Wang XG, Niu SD
- 卷号：
- 2011, 56(26): 2853-2861
- 页面范围：
- 2853-2861
- 是否译文：
- 否
- 发表时间：
- 2011-08-18