The evolution of pressure gain in turbulent fast flames
The evolution of pressure gain in turbulent fast flames
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DOI：
10.1016/j.combustflame.2021.111641
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发表时间：
2021-12
影响因子：
4.4
通讯作者：
Hardeo Chin;J. Chambers;Jonathan Sosa;A. Poludnenko;V. Gamezo;K. Ahmed
中科院分区：
文献类型：
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作者：
Hardeo Chin;J. Chambers;Jonathan Sosa;A. Poludnenko;V. Gamezo;K. Ahmed
这项研究量化的快速燃烧制度的特点是不同程度的压缩性和湍流火焰和冲击的压力的演变。实验探索是在湍流激波管设施，火焰的可压缩性的水平是通过改变氢-空气混合物的当量比来控制。高速粒子图像测速仪，化学发光，纹影，和压力测量同时获得捕捉停滞压力的各种制度从快速火焰冲击火焰复合物的上升。的压力和速度的测量结果被用来分析燃烧制度的兰金-Hugoniot图，显示了火焰驱动的压缩范围内的快速火焰条件发展到爆震发作。不同的压缩水平取决于激波-火焰耦合水平和火焰速度。较低程度的可压缩性示出了具有40%热效率的理想ZND循环的52%的效率，而示出了冲击-火焰复合体产生由具有53%热效率的理想ZND循环产生的功的81%。
This research quantifies the evolution of pressure for fast burning regimes characterized by various degrees of compressibility and involving turbulent flames and shocks. The experimental exploration is conducted in a Turbulent Shock Tube facility, where the level of flame compressibility is controlled by varying the equivalence ratio of the hydrogen-air mixture. High-speed particle image velocimetry, chemiluminescence, schlieren, and pressure measurements are simultaneously acquired to capture the rise in stagnation pressure for various regimes from fast flames to shock-flame complexes. The pressure and velocity measurements are used to analyze combustion regimes on the Rankine-Hugoniot diagram that shows the flame-driven compression for a range of fast flame conditions evolving toward detonation onset. Various levels of compression are dependent on the level of shock-flame coupling and flame velocities. Lower degrees of compressibility show 52% efficiency of an ideal ZND cycle with 40% thermal efficiency, while shock-flame complexes are shown to produce 81% of the work produced by an ideal ZND cycle with 53% thermal efficiency.