The effects of five coaxial triple swirler configurations on mass flow rate distribution, swirling flow structure, and Coanda flow formation to transition were investigated. The study utilized a numerical investigation with the Re-Normalization Group k−ε Turbulence model to simulate the internal and external flow field. An experimental setup was also provided to validate the numerical results using a Particle Image Velocimetry system. The swirling flow structure was classified into three categories: Coanda, Transient, and no-Coanda flows. Results showed that the transient swirling flow from the Coanda flow occurred with a slight change in the outer recess length, which can control the three flow categories. Also, the study found two types of swirling flow structures with cylindrical and bubble shapes with the change in the inner recess length, a key variable in controlling the swirling flow structure. Additionally, the study presented quantitative results to predict the formation of the Coanda flow using dimensionless parameters composed of momentum ratios of swirlers. Overall, the findings of this study provide valuable insights into the design and optimization of coaxial triple swirler configurations for practical applications.

中文翻译：

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同轴三旋流器中影响参数的柯安达流的产生

研究了五种同轴三旋流器配置对质量流量分布、旋流结构和柯恩达流形成到过渡的影响。该研究利用重新归一化群 k−ε 湍流模型进行数值研究来模拟内部和外部流场。还提供了实验装置来验证使用粒子图像测速系统的数值结果。旋流结构分为三类：柯恩达流、瞬态流和无柯恩达流。结果表明，柯恩达流的瞬态旋流发生时，外凹部长度略有变化，可以控制三种流动类别。此外，研究还发现，随着内凹部长度的变化，会出现圆柱形和气泡两种类型的旋流结构，而内凹部长度是控制旋流结构的关键变量。此外，该研究还提出了使用由旋流器动量比组成的无量纲参数来预测柯恩达流形成的定量结果。总的来说，这项研究的结果为实际应用中同轴三旋流器配置的设计和优化提供了宝贵的见解。