| 横向振动格栅紊流紊动特性试验 |
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| 引用本文： | 李文杰,刘华,杨胜发,王涛,张鹏. 横向振动格栅紊流紊动特性试验[J]. 水科学进展, 2016, 27(1): 49-56. DOI: 10.14042/j.cnki.32.1309.2016.01.006 |
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| 作者姓名： | 李文杰 刘华 杨胜发 王涛 张鹏 |
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| 作者单位： | 1.重庆交通大学国家内河航道整治工程技术研究中心, 重庆 400074; |
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| 基金项目： | 国家自然科学基金资助项目(51209241);交通运输部应用基础研究资助项目(2014329814310) |
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| 摘 要： | 建立了一套大尺度格栅紊流试验系统,格栅进行有别于传统垂向模式的横向振动,采用粒子图像测速技术(Particle Image Velocimetry,PIV)测量流速。对瞬时流速的检验表明,该系统产生的紊流场具有较强的随机性和统计规律性。均方根流速在格栅片附近变化较大,在两片格栅中间处趋于稳定,纵向均方根流速明显大于垂向均方根流速,二者比值在1.5~2.0之间,接近天然明渠紊流。雷诺应力在距格栅越近处波动越大,随着距格栅距离的增加而减小,至两片格栅中间处雷诺应力基本为0。时间和长度积分尺度在格栅片处最小,随着距格栅距离的增加而线性增加,至两片格栅中间处达到最大值。流速能谱呈现Kolmogorov理论的-5/3次方规律。本系统生成的紊流场的统计规律与传统的垂向振动格栅紊流较为一致,但纵向和垂向的紊动强度更接近实际,为后续紊流中泥沙和污染物等运动机理的研究奠定了基础。
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| 关 键 词： | 格栅紊流 横向振动 紊动特性 粒子图像测速 |
| 收稿时间： | 2015-07-28 |
Experimental study on the characteristics of longitudinal oscillating grid turbulence |
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| LI Wenjie,LIU Hua,YANG Shengfa,WANG Tao,ZHANG Peng. Experimental study on the characteristics of longitudinal oscillating grid turbulence[J]. Advances in Water Science, 2016, 27(1): 49-56. DOI: 10.14042/j.cnki.32.1309.2016.01.006 |
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| Authors: | LI Wenjie LIU Hua YANG Shengfa WANG Tao ZHANG Peng |
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| Affiliation: | 1.National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing 400074, China;2.Key Laboratory of Ministry of Education for Hydraulic and Water Tronsport Engineering, Chongqing Jiaotong University, Chongqing 400074, China;3.Changjiang Chongqing Harbor and Waterway Engineering Investigation and Design Institute, Chongqing 401147, China |
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| Abstract: | Oscillating grid turbulence is an efficient way of studying complex turbulence and mass transport, while the turbulence generated by the existing vertical oscillating grid systems is quite different from the natural turbulence. A large scale grid turbulence experiment system is established, the grids conduct longitudinal oscillating rather than the traditional vertical oscillating, and the Particle Image Velocimetry is used to measure the flow fields. Tests of the instantaneous flow velocities show that the turbulence generated by this system has strong randomness and statistical regularity. All the longitudinal and vertical root mean square velocities vary rapidly near the grids, and tend to be stable at the middle of the grids. The longitudinal root mean square velocities are larger than the vertical values, and the ratio is about 1.5-2.0, which is close to the natural open channel flow. The fluctuation of the Reynolds stress near the grids is relatively large and decreases with the increasing distance from the grid, the Reynolds stress is about zero at the middle of the grids. The integral time and length scales near the grids are the smallest and increase linearly with the increasing distance from the grids, reaching the maximum at the middle of the grids. The flow velocity spectra obeys the Kolmogorov-5/3 theory. The statistical characteristics of the turbulence generated by this system are consistent with the traditional vertical oscillating grid turbulence, but the longitudinal and vertical turbulent intensities are more close to the natural open channel flow, laying the foundation for the studies of sediment and pollutant transports. |
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| Keywords: | grid turbulence longitudinal oscillating turbulent characteristic particle image velocimetry |
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