中国物理B ›› 2022, Vol. 31 ›› Issue (7): 74702-074702.doi: 10.1088/1674-1056/ac4bd0

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Effects of single synthetic jet on turbulent boundary layer

Jin-Hao Zhang(张津浩)1, Biao-Hui Li(李彪辉)1, Yu-Fei Wang(王宇飞)1, and Nan Jiang(姜楠)1,2,†   

  1. 1 Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China;
    2 Key Laboratory of Modern Engineering Mechanics, Tianjin 300350, China
  • 收稿日期:2021-12-09 修回日期:2022-01-13 接受日期:2022-01-17 出版日期:2022-06-09 发布日期:2022-07-19
  • 通讯作者: Nan Jiang E-mail:nanj@tju.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11732010, 11972251, 11872272, 11902218, and 12172242) and the National Key Research and Development Program of the Ministry of Science and Technology, China (Grant No. 2018YFC0705300).

Effects of single synthetic jet on turbulent boundary layer

Jin-Hao Zhang(张津浩)1, Biao-Hui Li(李彪辉)1, Yu-Fei Wang(王宇飞)1, and Nan Jiang(姜楠)1,2,†   

  1. 1 Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China;
    2 Key Laboratory of Modern Engineering Mechanics, Tianjin 300350, China
  • Received:2021-12-09 Revised:2022-01-13 Accepted:2022-01-17 Online:2022-06-09 Published:2022-07-19
  • Contact: Nan Jiang E-mail:nanj@tju.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11732010, 11972251, 11872272, 11902218, and 12172242) and the National Key Research and Development Program of the Ministry of Science and Technology, China (Grant No. 2018YFC0705300).

摘要: The turbulent boundary layer (TBL) is actively controlled by the synthetic jet generated from a circular hole. According to the datasets of velocity fields acquired by a time-resolved particle image velocimetry (TR-PIV) system, the average drag reduction rate of 6.2% in the downstream direction of the hole is obtained with control. The results of phase averaging show that the synthetic jet generates one vortex pair each period and the consequent vortex evolves into hairpin vortex in the environment with free-stream, while the reverse vortex decays rapidly. From the statistical average, it can be found that a low-speed streak is generated downstream. Induced by the two vortex legs, the fluid under them converges to the middle. The drag reduction effect produced by the synthetic jet is local, and it reaches a maximum value at x+=400, where the drag reduction rate reaches about 12.2%. After the extraction of coherent structure from the spatial two-point correlation analysis, it can be seen that the synthetic jet suppresses the streamwise scale and wall-normal scale of the large scale coherent structure, and slightly weakens the spanwise motion to achieve the effect of drag reduction.

关键词: turbulent boundary layer, synthetic jet, hairpin vortex, drag reduction

Abstract: The turbulent boundary layer (TBL) is actively controlled by the synthetic jet generated from a circular hole. According to the datasets of velocity fields acquired by a time-resolved particle image velocimetry (TR-PIV) system, the average drag reduction rate of 6.2% in the downstream direction of the hole is obtained with control. The results of phase averaging show that the synthetic jet generates one vortex pair each period and the consequent vortex evolves into hairpin vortex in the environment with free-stream, while the reverse vortex decays rapidly. From the statistical average, it can be found that a low-speed streak is generated downstream. Induced by the two vortex legs, the fluid under them converges to the middle. The drag reduction effect produced by the synthetic jet is local, and it reaches a maximum value at x+=400, where the drag reduction rate reaches about 12.2%. After the extraction of coherent structure from the spatial two-point correlation analysis, it can be seen that the synthetic jet suppresses the streamwise scale and wall-normal scale of the large scale coherent structure, and slightly weakens the spanwise motion to achieve the effect of drag reduction.

Key words: turbulent boundary layer, synthetic jet, hairpin vortex, drag reduction

中图分类号:  (Drag reduction)

  • 47.85.lb
47.85.ld (Boundary layer control) 47.27.nb (Boundary layer turbulence ?) 47.27.De (Coherent structures)