Abstract Propagation of one-dimensional planar flames laden with fuel droplets is theoretically investigated in this work. Localized homogeneous and heterogeneous flames are considered, characterized by different relative locations of dispersed droplets and propagating flame front. With the assumption of large activation energy for the chemical reaction, correlations describing flame propagation speed, flame temperature, evaporation onset front and completion front are derived. The influences of droplet and fuel properties on propagation of fuel-droplet-laden planar flames are studied. The results indicate that the flames are enhanced under fuel-lean conditions but weakened under fuel-rich conditions. Both effects are intensified with increased droplet mass loading. Fuel vapor and temperature gradient are observed in the post-flame evaporation zone of heterogeneous flames. Evaporation completion front location is considerably affected by the droplet diameter, but the evaporation onset front varies little with droplet properties. Flame bifurcation occurs with high droplet mass loading under fuel-rich mixture, leading to multiplicity of flame propagation speed as well as droplet evaporation onset and completion fronts. Sprayed fuels with larger latent heat of vaporization would weaken the flame enhancement effect under fuel-lean conditions, due to larger evaporation heat loss. Moreover, for homogeneous flames, evaporative heat loss only occurs in the pre-flame zone. However, for heterogeneous flames, heat loss from the post-flame evaporation zone becomes dominant for relatively large droplets. Besides, for fuel-lean mixtures laden with medium-sized fuel droplets, the propagation speed of heterogeneous flames increases with Lewis number, due to the enhanced fuel vapor diffusion in the post-flame zone.

中文翻译：

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燃料液滴雾中非均质和均质平面火焰的传播

摘要 本文从理论上研究了载有燃料液滴的一维平面火焰的传播。考虑了局部均质和非均质火焰，其特征在于分散的液滴和传播的火焰前沿的不同相对位置。假设化学反应的活化能大，则推导出描述火焰传播速度、火焰温度、蒸发起始前沿和完成前沿的相关性。研究了液滴和燃料特性对载有燃料液滴的平面火焰传播的影响。结果表明，在贫燃料条件下火焰增强，而在富燃料条件下减弱。随着液滴质量负载的增加，这两种效果都会得到加强。在非均质火焰的后火焰蒸发区观察到燃料蒸汽和温度梯度。蒸发完成前沿位置受液滴直径的影响很大，但蒸发起始前沿随液滴特性变化很小。在富含燃料的混合物下，高液滴质量负载会发生火焰分叉，导致火焰传播速度的多样性以及液滴蒸发开始和完成前沿。汽化潜热较大的喷雾燃料会由于较大的蒸发热损失而减弱贫燃料条件下的火焰增强效果。此外，对于均质火焰，蒸发热损失仅发生在预燃区。然而，对于异质火焰，来自火焰后蒸发区的热损失对于相对较大的液滴来说变得占主导地位。除了，