Asymptotic Analysis on High-temperature Premixed Flames: Instability of Flame Fronts under the Constant-enthalpy Conditions
Asymptotic Analysis on High-temperature Premixed Flames: Instability of Flame Fronts under the Constant-enthalpy Conditions
复制标题
高温预混火焰渐近分析：恒焓条件下火焰锋面的不稳定性
DOI：
10.1299/jtst.5.1
复制
发表时间：
2010
影响因子：
1.2
通讯作者：
S. Kadowaki
中科院分区：
文献类型：
--
作者：
S. Kadowaki
对高温可燃混合物预混火焰进行了渐近分析，阐明了火焰锋面的不稳定性。对足够低马赫数的平面预混火焰进行了处理，并假设了具有足够高活化能的一步不可逆化学反应。通过渐近分析，得到了燃烧速度随燃烧气体温度和未燃烧气体温度以及燃料质量分数的变化公式。为了研究高温预混火焰在等焓条件下的不稳定性，在燃烧气体温度恒定的情况下，得到了与燃烧速度和燃烧气体与未燃烧气体的温度比有关的不稳定性强度。除未燃气体密度不变条件下反应指数较低的预混火焰外，随着未燃气体温度的升高，不稳定强度增大。这是因为不稳定强度是由燃烧速度的增加和温度比的降低之间的竞争决定的。
Asymptotic analysis on premixed flames with high-temperature combustible mixtures was performed to elucidate the instability of flame fronts. Planar premixed flames with sufficiently low Mach numbers were treated, and a one-step irreversible chemical reaction with sufficiently high activation energy was assumed. Through the asymptotic analysis, we obtained the formula for the burning velocity, depending on the temperature of burned and unburned gases and on the mass fraction of fuel. To investigate the instability of high-temperature premixed flames under the constant-enthalpy conditions, we obtained the instability intensity which depended on the burning velocity and on the temperature ratio of burned and unburned gases, where the burned-gas temperature was constant. As the unburned-gas temperature became higher, the instability intensity became higher, except for premixed flames with low reaction exponents under the conditions of constant-density unburned gases. This was because that the instability intensity was determined by the competition between the increase of the burning velocity and the decrease of the temperature ratio.