过滤燃烧火焰锋面倾斜演变的二维数值研究

Two-Dimensional Numerical Study of Inclination Flame Evolution in Porous Media

通过二维双温模型研究过滤燃烧火焰锋面倾斜的演化规律。给定初始倾斜角度(8°),甲烷/空气在当量比为0.2～0.5,流速为0.4～1.2 m/s的范围内,研究倾斜火焰锋面的演变。结果表明,在流速较大时,火焰锋面演化类似于S形的火焰;在流速较小时,火焰锋面演化为特征火焰。分析表明,形成以上火焰的原因是由于初始倾斜火焰在燃烧器中径向不同位置的传播速度不同。数值计算捕捉到了倾斜火焰发展的基本形态。

Flame inclination evolutions in porous media are numerically investigated using two-temperature two-dimensional numerical model.Inclination instabilities during the flame propagation in porous media are analyzed by initially imposed an inclined angle（8°）of high solid temperature under the conditions of velocity u_g=0.4～1.2 m/s and equivalence ratioφ=0.2～0.5 for CH_4/Air mixture.It is found that the inclined flame evolution to S-shaped flame at the greater velocity, whereas a characteristic inclination flame occurs at smaller velocity.Results shows that the different combustion wave speeds at the radial position lead to formation the S-typed and characteristic inclination flame in porous media burner.Numerical model captured the basic flame shape and show qualitative agreements with experimental data.