Flame kernel evolution and shock wave propagation with laser ignition in ethanol-air mixtures
Flame kernel evolution and shock wave propagation with laser ignition in ethanol-air mixtures
复制标题
乙醇-空气混合物中激光点火的火焰核演化和冲击波传播
DOI：
10.1016/j.apenergy.2018.10.017
复制
发表时间：
2019
期刊：
影响因子：
11.2
通讯作者：
Hongming Xu
中科院分区：
文献类型：
--
作者：
Xiuchao Bao;Amrit Sahu;Yizhaou Jiang;Tawfik Badawy;Hongming Xu
利用高速纹影摄影技术研究了定容燃烧室中激光点火下乙醇/空气混合物火焰核的演化和激波传播过程。在初始压力为0.1 MPa和温度为333 K，点火进行了使用脉冲激光在第二谐波波长与六个不同的激光能量从75至200 mJ，当量比范围从0.8至1.4。在激光触发后约3.0 µs，捕获到十字形等离子体斑点，而火焰核的形状最初是圆形的，然后转变为椭圆体结构。随着等离子体的收缩，火焰核的生长速率最初在四个方向上非常不同，然后接近稳定的火焰速度。等离子体区的收缩伴随着快速的冲击波传播，其中，波的传播速度被发现是可以忽略不计的影响，无论是激光能量或混合物当量比的变化。在本研究的乙醇/空气混合物试验条件下，初始冲击波速度为480 m/s，20 µs后衰减至380 m/s。当t < 20 µs时，冲击波阵面的传播与时间的关系约为t0.6，然后它变成时间的近似线性函数。
Flame kernel evolution and shock wave propagation in ethanol/air mixtures with laser ignition in a constant-volume chamber was investigated by means of high-speed Schlieren photography. At initial pressure of 0.1 MPa and temperature of 333 K, ignition was performed using a pulsed laser at the second harmonic wavelength with six different laser energies from 75 to 200 mJ, for the equivalence ratios ranging from 0.8 to 1.4. A cross-shaped plasma spot is captured ∼3.0 µs after the laser triggering, whereas the shape of the flame kernel is initially circular and then transforms to an ellipsoid structure. Following the contraction of the plasma, the flame kernel growth rate is initially very different in the four directions and then approaches a steady flame speed. The contraction of the plasma zone is accompanied by a rapid shock wave propagation where, the wave propagation speed is found to be negligibly influenced by the variations in either laser energy or mixture equivalence ratio. Under the test conditions in this study for ethanol/air mixtures, the initial shock wave speed is ∼480 m/s which decays to ∼380 m/s after 20 µs. The shock wave front propagates with a time dependency of about t0.6when t < 20 µs, and then it becomes an approximately linear function of time.
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DOI：
10.1016/j.proci.2016.06.131
发表时间：
2017
期刊：
--
影响因子：
--
作者：
H. Torikai;Y. Soga;A. Ito
通讯作者：
H. Torikai;Y. Soga;A. Ito
影响因子：
4.4
作者：
I. Mulla;S. Chakravarthy;N. Swaminathan;R. Balachandran
通讯作者：
I. Mulla;S. Chakravarthy;N. Swaminathan;R. Balachandran
影响因子：
7.2
作者：
M. Weinrotter;H. Kopecek;E. Wintner;M. Lackner;F. Winter
通讯作者：
M. Weinrotter;H. Kopecek;E. Wintner;M. Lackner;F. Winter
影响因子：
4.6
作者：
D. Srivastava;Kewal Dharamshi;A. Agarwal
通讯作者：
D. Srivastava;Kewal Dharamshi;A. Agarwal
高重复纳秒激光诱导等离子体稳定预混合甲烷-空气火焰
影响因子：
5
作者：
于杨;李晓晖;安小康;于欣;樊荣伟;陈德应;孙锐
通讯作者：
孙锐