The effect of a non-axisymmetric inlet ports configuration of an internal-mixing twin-fluid atomizer on the spray characteristics is experimentally investigated. Inside the atomizer, two water jets are impinged on each other and are further disrupted by a central gas stream coming from the top. The operating conditions consider the variation of the gas mass flow rate at Reynolds and Weber numbers in the order of 10⁴−10⁵. Phase Doppler anemometry (PDA) measurements at four radial, four axial, and two perpendicular azimuthal positions are combined with a patternator device to obtain droplet size, axial velocity, and mass flux distributions. An approach for evaluating the overall spray asymmetry based on the mass flux distributions is proposed, which enabled the detection of slight asymmetries throughout the azimuthal direction, where especially differences in droplet sizes and velocities measured between the two azimuthal positions are observed. Higher Sauter mean diameters (SMDs) and lower velocities in regions of the spray with higher liquid mass flux are observed when compared to the azimuthal position perpendicular to it. In general, the liquid is considerably faster in the spray center than at the boundaries, where the fluctuating component of the velocity is higher due to the interaction of small droplets with the surrounding air. Overall, an increase in the gas flow rate reduces the droplet sizes and increases the velocity across the spray.

中文翻译：

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非轴对称入口端口和操作条件对内部混合雾化器液滴动力学的影响

实验研究了内部混合双流体雾化器的非轴对称入口配置对喷雾特性的影响。在雾化器内部，两个水射流相互撞击，并被来自顶部的中央气流进一步扰乱。操作条件考虑雷诺数和韦伯数下气体质量流量的变化，数量级为 10 ⁴ −10 ⁵. 四个径向、四个轴向和两个垂直方位角位置的相位多普勒风速测量 (PDA) 测量与图案仪装置相结合，以获得液滴尺寸、轴向速度和质量通量分布。提出了一种基于质量通量分布评估整体喷雾不对称性的方法，该方法能够检测整个方位角方向的轻微不对称性，特别是观察到两个方位角位置之间测量的液滴尺寸和速度的差异。与垂直于它的方位角位置相比，在具有较高液体质量通量的喷雾区域中观察到更高的 Sauter 平均直径 (SMD) 和更低的速度。一般来说，液体在喷雾中心比在边界快得多，由于小液滴与周围空气的相互作用，速度的波动分量较高。总的来说，气体流速的增加会减小液滴尺寸并增加喷雾的速度。