As a key parameter for describing the microscopic characteristics of fuel spray, the Sauter mean diameter (SMD) is widely applied for evaluating the spray effect. Researchers have proposed several formulas for predicting the SMD under different experimental conditions. However, there are two main limitations. First, only the physical properties of the fuel and initial injection parameters are considered; the effect of airflow on SMD is not considered. Second, the spray affected by airflow disperses more widely and causes the SMD to vary in different regions. Hence, a single universal SMD evaluation cannot adequately describe the particle size distribution in each region of the spray under cross-flow conditions. Therefore, this paper proposes a prediction formula for multi-zone SMD under cross-flow conditions. In this study, the particle velocity and diameter were measured using a particle image analysis experimental system in different spray regions. The relationship between SMD and fuel properties, cross-flow speed, particle velocity, and injection conditions were analyzed. Moreover, accurate prediction formulas were established that can be applied to calculate the SMD in different regions of the fuel spray under cross-flow conditions.

中文翻译：

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横流条件下燃油喷雾的多区域Sauter平均直径模型

作为描述燃油喷雾的微观特性的关键参数，索特平均直径（SMD）被广泛用于评估喷雾效果。研究人员提出了几种在不同实验条件下预测SMD的公式。但是，有两个主要限制。首先，仅考虑燃料的物理特性和初始喷射参数；没有考虑气流对SMD的影响。其次，受到气流影响的喷雾分散得更广，并导致SMD在不同区域发生变化。因此，单一通用SMD评估无法充分描述在错流条件下喷雾剂每个区域的粒径分布。因此，本文提出了横流条件下多区域SMD的预测公式。在这个研究中，使用颗粒图像分析实验系统在不同的喷雾区域测量颗粒的速度和直径。分析了SMD与燃料性能，错流速度，颗粒速度和喷射条件之间的关系。此外，建立了准确的预测公式，该公式可用于计算错流条件下燃油喷雾不同区域的SMD。