Active control of wall-bounded turbulence for drag reduction with piezoelectric oscillators Project supported by the National Natural Science Foundation of China (Grant Nos. 11332006, 11732010, 11572221, and 11502066). |
(color online) Scale-dependent energy distribution: (a) SYN vibration at different frequencies, (b) SYN/ASYN vibration at the same voltage, (c) SYN vibration at different voltages, (d) ASYN vibration at different voltages. |