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›› 2011, Vol. 11 ›› Issue (1): 1-8.

• 流动与传递 •    下一篇

新型循环射流混合器湍流特性分析

禹言芳 吴剑华 孟辉波   

  1. 沈阳化工大学机械工程学院 沈阳化工大学机械工程学院 沈阳化工大学机械工程学院
  • 收稿日期:2010-12-28 修回日期:2011-01-26 出版日期:2011-02-20 发布日期:2011-02-20
  • 通讯作者: 孟辉波

Turbulent Characteristics of a Novel Circulating Jet Mixer

YU Yan-fang WU Jian-hua MENG Hui-bo   

  1. College of Mechanical Engineering, Shenyang University of Chemical Technology College of Mechanical Engineering, Shenyang Institute of Chemical Technology College of Mechanical Engineering, Shenyang University of Chemical Technology
  • Received:2010-12-28 Revised:2011-01-26 Online:2011-02-20 Published:2011-02-20
  • Contact: MENG Hui-bo

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摘要： 采用Fluent SST k-w湍流模型，分别对新型循环射流混合器受限区域内喷嘴射流自相似性和挡板长度对射流轴线衰减规律进行了数值研究. 对自由湍动圆射流在不同轴向距离下数值模拟所得无量纲速度衰减曲线与理论曲线吻合较好. 通过三维湍流流场分析对混合器内流体流动进行分区，并利用涡量分布分析混合器内的流体循环流动情况. 结果表明，在z/H=0.25时，平均涡量达最大值áw?max=11.22. 相平面角度qp<20o时，áw?为正，其余为负. 特别是qp=16o时，áw?max=27.22；qp=20o时，áw?min=-100.66. 由剪切速率分布得出较大的剪切速率分布于尾涡的位置. 最后给出了强化混合效果应考虑的因素.

关键词: 循环射流, 自相似性, 涡量, 剪切速率

Abstract: SST k-w turbulence model was employed to simulate the turbulent flow field of a novel circulating jet mixer. The similarity of confined zone jet and the decay of jet axial velocity at various baffle lengths were carried out. The decay of dimensionless jet axial velocity by simulation was in good accordance with theoretical curve for free turbulent jet. The fluid zone in the jet mixer was divided into four sub-regions based on the three-dimension velocities. The fluid circulating flow in the novel jet mixer was studied by vorticity and the average vorticity áw? with different axial positions and phase planes. The results show that the maximum value of áw? is 11.22 at z/H=0.25. áw? is positive at qp<20o, while at other qp it is negative. The maximum value of áw? is 27.22 which is located at qp=16o, and the minimum value of áw? is -100.66 at qp=20o. The simulation result of shear rate reveals that the larger value is located in the trailing vortex. The factors for enhancing the mixing effect are put forward.

Key words: jet mixer, self-similarity, vorticity, shear rate

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