摘要
采用氢气泡技术并结合高速摄像技术,对双圆柱绕流进行可视化实验研究。实验结果分析表明,来流对称、流速一定的情况下,间距比的改变将出现偏流。随着间距的减小,偏流现象更加明显,且流动的偏向是随机的。改变圆柱位置使来流方向与两圆柱连心线平行,当间距比为1.5时,两圆柱的流动相当于一个钝体的绕流,且前后圆柱均有对称涡出现。当间距比增大到一定值时,前排对后排的扰动将消失,此时涡脱落比较显著。这些结论可对换热器中叉排、顺排管间距的布置提供参考。
Visualization experiments of crossflow over two circular cylinders were carried out in this paper using the hydrogen bubble method and a high-speed video camera. Experimental results show that for a symmetric upstream with a constant velocity, a change of pitch between the two cylinders will lead to flow deviation. The flow deviation phenomenon will be more apparent when the pitch becomes smaller, and the flow deviation is random. When the flow direction is parallel to the connnecting line of the two cylinder centres and the dimensionless pitch is 1.5, the crossflow over two circular cylinders is similar to that for a blunt body and symmetric swirls will appear in the downstream regions of both cylinders. When the dimensionless pitch increases to a certain value, the disturbance of the first cylinder to the second will disappear and vortex shedding will now be more notable. The conclusions can give a reference to the design of heat exchangers with aligned or staggered tube arrangements.
出处
《能源研究与信息》
2010年第1期39-43,共5页
Energy Research and Information
关键词
圆柱绕流
氢气泡技术
尾流
图像处理
crossflow over circular cylinder
hydrogen bubble method
wake
image processing
