To explore the flow field of micro-mixing jets, cold flow characteristics of a model Micromix burner were investigated by particle image velocimetry (PIV) system and Large-eddy simulation (LES) model. Results show that LES results are in good agreement with experimental results. In the flow field of multiple micro-mixing jets, the jet velocities of nozzles farther away from the burner center have a high increase and decay rate. When the outlet Reynolds number increases, the Reynolds stress increases first and then decreases in the merging region indicating that the velocity fluctuation disappears in the second jet half, but it has little effect on the flow field structure. Comparing the flow fields of round multiple micro-mixing jets, the merging point and combined point in the elliptical jets flow field move backward. Moreover, the maximum velocity for elliptical jets is also faster than the round jets, which is caused by the high turbulent kinetic energy in the elliptical jet flow field. When the tube spacing increases from 2 to 3 times the tube diameter, positions of the two feature points change linearly. Further, the surrounding jets can decrease the velocity attenuation of the center nozzle and elongate the axial length of the two feature regions.

中文翻译：

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富氢燃气轮机多元微混合射流低温流动特性的实验和数值研究


为探究微混合射流的流场，采用粒子图像测速 （PIV） 系统和大涡模拟 （LES） 模型研究了模型 Micromix 燃烧器的低温流动特性。结果表明，LES 结果与实验结果吻合较好。在多个微混合射流的流场中，远离燃烧器中心的喷嘴的射流速度具有较高的增加和衰减速率。当出口雷诺数增加时，合并区的雷诺应力先增大后减小，表明速度波动在第二射流半场消失，但对流场结构影响不大。比较圆形多个微混合射流的流场，椭圆射流流场中的合并点和合并点向后移动。此外，椭圆射流的最大速度也比圆形射流快，这是由椭圆射流流场中的高湍流动能引起的。当管间距从管径的 2 倍增加到 3 倍时，两个特征点的位置会线性变化。此外，周围的射流可以减小中心喷嘴的速度衰减并拉长两个特征区域的轴向长度。