Influence of Momentum and Heat Losses on the Large-Scale Stability of Quasi-2D Premixed Flames
Influence of Momentum and Heat Losses on the Large-Scale Stability of Quasi-2D Premixed Flames
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动量和热损失对准二维预混火焰大尺度稳定性的影响
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
G. Sivashinsky
中科院分区：
文献类型：
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作者：
G. Joulin;G. Sivashinsky
摘要我们考虑了预混气体火焰在平行平板（Hele-Shaw单元）之间的传播，并定性地分析了动量和热量的损失如何影响火焰的稳定性，因为波长的湍流明显超过了平板间距。模拟火焰作为一个有效的接口，并使用欧拉-达西方程的气体两侧，我们首先表明，摩擦绝热壁修改Landau-Darrieus不稳定性在两个方面：阻尼系数带来的，沿着与Saffman-Taylor型的不稳定性。由于摩擦引起的压力梯度，后者甚至可能主导重力对窄通道中向下传播的锋面的稳定影响。由于它们最终使气体密度恢复其上游值，热损失倾向于缓和这些影响，以及Landau-Darrieus不稳定性和重力的影响，但当热损失和重力的影响时，长波长的湍流在向下传播中可能保持不稳定。
ABSTRACT We consider premixed gaseous flames propagating between parallel plates (Hele-Shaw cell) and qualitatively analyze how the resulting losses of momentum and heat affect the flame stability for wavelengths of wrinkling that noticeably exceed the plate spacing. Modelling the flame as an effective interface and using Euler-Darcy equations for the gas on both sides, we firstly show that friction to adiabatic walls modify the Landau-Darrieus instability in two ways: a damping coefficient is brought in, along with a Saffman-Taylor type of instability. Being due to friction-induced pressure gradients, the latter may even dominate the stabilizing influence of gravity for downwardly propagating fronts in narrow channels. Because they ultimately make the gas density resume its upstream value, heat losses tend to moderate these effects, as well as the Landau-Darrieus instability and the influence of gravity, but the long wavelengths of wrinkling may remain unstable in downward propagations when heat losses a...