Active control of wall-bounded turbulence for drag reduction with piezoelectric oscillators

• 来源期刊: 中国物理B（英文版）
• 关键词: turbulent boundary layer active control double piezoelectric vibrators
• 年，卷（期）: 2018,（7）
• 页码范围: 453-460
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/7/074701

摘要

An experimental investigation was performed for active control of coherent structure bursting in the near-wall region of the turbulent boundary layer. By means of synchronous and asynchronous vibrations with double piezoelectric vibrators, the influence of periodic vibration of the double piezoelectric vibrators on the mean velocity profile, drag reduction rate, and coherent structure bursting is analyzed at Reθ =2766. The case with 100 V/160 Hz-ASYN is superior to other conditions in the experiment and a relative drag reduction rate of 18.54％ is exciting. Asynchronous vibration is more effective than synchronous vibration in drag reduction at the same voltage and frequency. In all controlled cases, coherent structures at large scales are regulated while the small-scale structures are stimulated. The fluctuating velocity increases significantly. A periodic regulating effect on the coherent structure can be seen in the ASYN control conditions at the frequency of 160 Hz.