General correlations of high pressure turbulent burning velocities with the consideration of Lewis number effect
General correlations of high pressure turbulent burning velocities with the consideration of Lewis number effect
复制标题
考虑路易斯数效应的高压湍流燃烧速度的一般相关性
DOI：
10.1016/j.proci.2018.08.049
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发表时间：
2019
影响因子：
3.4
通讯作者：
S. Shy
中科院分区：
文献类型：
--
作者：
M. T. Nguyen;D. Yu;S. Shy
本研究测量了不同有效刘易斯数（Le）的液体和气体燃料/空气混合物球形膨胀火焰的高压湍流燃烧速度（ST），即在T= 423 K时，预蒸发化学计量异辛烷的Le为1.43，在298 K时，当量比为0.6的氢气的Le为0.58，和丙烷在ε = 0.7与Le ε 1.62在298 K，使用相同的双室，风扇搅拌十字形燃烧器能够产生近各向同性的湍流。高速纹影成像用于获得平均火焰半径< R（t）>的时间增长和观察到的火焰速度S F和/或d< R>/dt，其中S F是< R（t）>的斜率，等于< R>25 mm≤< R（t）>≤ 45 mm范围内d /dt的平均值。使用密度校正和布拉德利的纹影球形火焰平均进展变量转换因子，从c = 0.1到0.5，S T，c= 0.5 B/ρ u）S F（< R>c= 0.1/< R>c= 0.5）2，其中下标B和u表示已燃烧和未燃烧的气体。结果表明，在任意给定脉动速度（u′）和压力（p）的条件下，Le< 1火焰的S T，c= 0.5远高于Le> 1火焰。我们发现这些非常散射的ST，c= 0.5数据与Le < 1 and Le>1和以前的甲烷数据在300 K/423 K与Le 1可以很好地表示由三个修改的一般关联最初提出的小林等人。（2005），Chaudhuri等人（2012）和Shy et al.（2012），当他们的缩放参数是重新缩放和分组与Le-1，每个代表一个单一的曲线与小数据分散。这表明湍流球形火焰可能存在自相似传播，而与所用燃料T、p、u′无关。讨论和比较与布拉德利（1992年）的相关性和未来的研究确定。
This study measures high-pressure turbulent burning velocities (S T) of spherical expanding flames for various liquid and gaseous fuel/air mixtures with different effective Lewis number (Le), ie pre-vaporized stoichiometric iso-octane with Le≈ 1.43 at T= 423 K, hydrogen at the equivalence ratio ϕ= 0.6 with Le≈ 0.58 at 298 K, and propane at ϕ= 0.7 with Le≈ 1.62 at 298 K, using the same dual-chamber, fan-stirred cruciform burner capable of generating near-isotropic turbulence. High-speed schlieren imaging is used to obtain the temporal growth of mean flame radii< R (t)> and the observed flame speeds, S F and/or d< R>/dt, where S F is the slope of< R (t)> which equals the average of d< R>/dt within 25 mm≤< R (t)>≤ 45 mm. Using the density correction and Bradley's mean progress variable converting factor for schlieren spherical flames from c¯= 0.1 to 0.5, S T, c= 0.5≈(ρ b/ρ u) S F (< R> c= 0.1/< R> c= 0.5) 2, where the subscripts b and u indicate the burned and unburned gas. Results show that Le< 1 flames have much higher S T, c= 0.5 than that of Le> 1 flames at any given rms turbulent fluctuating velocities (u′) and pressure (p). We find that these very scattering S T, c= 0.5 data with Le< 1 and Le> 1 together with previous methane data at 300 K/423 K with Le≈ 1 can be well represented by three modified general correlations originally proposed by Kobayashi et al.(2005), Chaudhuri et al.(2012), and Shy et al.(2012) when their scaling parameters are rescaling and grouping with Le− 1, each representing a single curve with small data scattering. This suggests a possible self-similar propagation for turbulent spherical flames, regardless of different fuels, T, p, u′ used. Discussion and comparison with the Bradley's correlation (1992) are offered and future studies identified.
影响因子：
3.4
作者：
Kobayashi, H;Seyama, K;Ogami, Y
通讯作者：
Ogami, Y