Three dimensional measurements of surface areas and burning velocities of turbulent spherical flames
Three dimensional measurements of surface areas and burning velocities of turbulent spherical flames
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DOI：
10.1016/j.combustflame.2021.111586
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发表时间：
2021-11
影响因子：
4.4
通讯作者：
P. Ahmed;B. Thorne;M. Lawes;S. Hochgreb;G. Nivarti;R. Cant
中科院分区：
文献类型：
--
作者：
P. Ahmed;B. Thorne;M. Lawes;S. Hochgreb;G. Nivarti;R. Cant
采用基于Mie散射的高频摆动激光片光技术，对不同甲烷-空气和氢气-空气混合气体中球形膨胀火焰的三维湍流火焰表面积和已燃气体进行了测量。相应的湍流燃烧速度，同时测量使用的压力上升率，在湍流均方根速度在0.3和2.0米/秒之间。测量了湍流燃烧速度增强与火焰表面积增强的比值ut m/ul与湍流均方根速度的关系。对于甲烷-空气火焰，湍流燃烧速度的增加与火焰表面积的增加接近。对于氢-空气火焰，前者可以超过后者的一个因素高达6倍的最大值的湍流均方根速度测试。大的差异表明，在氢-空气火焰的情况下，测量的每单位火焰面积的燃烧速率显着增强的湍流。对于重建的A3 D/a3 D，还讨论了相应的A2 D/a2 D.
Measurements of 3D turbulent flame surface area and burnt gas were carried out for spherically expanding flames in different methane-air and hydrogen-air mixtures using a high frequency swinging laser sheet technique based on Mie scattering. The corresponding turbulent burning velocities were measured simultaneously using the rate of pressure rise, at turbulence rms velocities between 0.3 and 2.0 m/s. The ratio of turbulent burning velocity enhancement u t m/u l to flame surface area enhancement A 3 D/a 3 D was measured as a function of turbulence rms velocity. For the methane-air flames, the turbulent burning velocity enhancement is close to that of the flame surface area enhancement. For the hydrogen-air flames, the former can exceed the latter by a factor of up to 6 at the largest values of turbulence rms velocity tested. The large discrepancy suggests that in the case of hydrogen-air flames, the measured rate of burning per unit flame area is significantly enhanced by the turbulence. For the reconstructed A 3 D/a 3 D, the corresponding A 2 D/a 2 D are also discussed.