Influence of swirling flow on mass and momentum transfer downstream of a pipe with elbow and orifice
Influence of swirling flow on mass and momentum transfer downstream of a pipe with elbow and orifice
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DOI：
10.1016/j.ijheatmasstransfer.2015.08.087
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发表时间：
2016
影响因子：
5.2
通讯作者：
Tsuyoshi Takano;Yuya Ikarashi;Kazuya Uchiyama;T. Yamagata;N. Fujisawa
中科院分区：
文献类型：
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作者：
Tsuyoshi Takano;Yuya Ikarashi;Kazuya Uchiyama;T. Yamagata;N. Fujisawa
实验研究了旋流对弯头孔口管道下游质量和动量传递的影响。在雷诺数re = 3 × 104的管道中，对旋转旋流器驱动的不同量级的涡流强度进行了实验。采用石膏溶解法和立体PIV分别测量了孔板下游的传质系数和横截面速度场。研究发现，随着旋流强度的增加，传质系数和湍流能量逐渐增大，而在弯头入口处，当旋流强度大于0.6时，传质系数和湍流能量在孔口下游变得非轴对称，高旋流强度时，传质系数和湍流能量趋于饱和。最大传质系数在孔板下游1个直径处出现峰值，达到无旋流直管传质系数的6倍。最大传质系数与旋流强度的关系在近壁湍流能量中也得到了类似的观察。
The influence of swirling flow on mass and momentum transfer downstream of a pipe with elbow and orifice is studied experimentally. The experiments are carried out in the pipe at Reynolds numberRe= 3 × 104for various magnitudes of swirl intensity up to 0.9 driven by the rotary swirler. The mass transfer coefficient and the cross-sectional velocity field downstream of the orifice are measured by the plaster dissolution method and the stereo PIV, respectively. It is found that the mass transfer coefficient and the turbulent energy increases gradually with increasing the swirl intensity, while they become non-axisymmetric downstream of the orifice for the swirl intensity larger than 0.6 at the inlet of the elbow, which is followed by the saturation at higher swirl intensity. The maximum mass transfer coefficient is found to have a peak at one diameter downstream of the orifice and it reaches 6 times larger value than that of the straight pipe without swirling flow. The behavior of the maximum mass transfer coefficient with respect to the swirl intensity is similarly observed in the near-wall turbulent energy.