This paper describes an experimental investigation of a linearly-arranged multiple-injection system of three swirling spray flames, simulating an unfolded sector of an annular combustor. Here we focus on the central flame placed in the basin of a pressure-antinode (PAN) of a standing transverse wave. Its response, quantified by means of the rms CH* amplitude filtered at the forcing frequency f_r, is studied as a function of the acoustic pressure rms amplitude reduced by the bulk aerodynamic pressure, Π, and parameterized by the flame power $\mathbb{P}$. As Π increases, three zones are identified: a linear growth, a transition zone and a saturation zone. Data in the linear growth and transition zone reduced by an adequate parameter merge into a unique self-similar curve whatever $\mathbb{P}$. In the saturation zone, the time-frequency analysis applied to photomultiplier signals shows that the frequency signal at f_r degrades in intensity level and uniformity, showing a loss of robustness in the flame response to the acoustic forcing over time. The gas phase displays strongly oscillating aerodynamics that can disrupt the central recirculation zone and destructure the mixing process. The liquid-phase shows a severe space-time modulation in droplet distribution and properties at high Π. Droplets are mainly found in an annular domain, characterized by a large time-dependence and inhomogeneity: a few quite big and slow fuel droplets are detected when the acoustic pressure P′(t) is positive, while a large population of small and rapid droplets is found when P′(t) is negative. In contrast, a little populated central core widens at positive P′(t) and fills up with big and slow droplets at negative P′(t). Such a periodic clustering might thus slow down the evaporation process.

本文描述了一个线性布置的多重喷射系统的实验研究，该系统具有三个旋转的喷射火焰，模拟了环形燃烧器的展开扇形。在这里，我们集中于放置在驻波横波的压力波腹（PAN）盆中的中心火焰。研究其响应，该响应通过在强制频率f _r处滤波的rms CH *幅度进行量化，并作为声压rms幅度的函数进行研究，该幅度由整体空气动力压力Π降低，并通过火焰功率进行参数化$\mathbb{P}$。随着Π的增加，确定了三个区域：线性增长，过渡区域和饱和区域。线性增长和过渡区域中的数据（通过适当的参数减少）合并为唯一的自相似曲线$\mathbb{P}$。在饱和区，对光电倍增管信号进行的时频分析表明，频率为f _r的频率信号强度水平和均匀性下降，表明火焰对声强迫的响应随时间推移而失去了鲁棒性。气相显示出强烈振荡的空气动力学特性，会破坏中央再循环区并破坏混合过程。液相在高Π下显示出液滴分布和特性的严重时空调制。液滴主要存在于环形区域，具有较大的时间依赖性和不均匀性：当声压P ′（t）是正值，而当P '（t）为负值时，会发现大量的小液滴和快速液滴。相反，少量填充的中心核在正P '（t）处变宽，并在负P '（t）处充满大而慢的液滴。这样的周期性聚类因此可能减慢蒸发过程。