Active control of vortex shedding: An explanation of the gain window.
SJ Illingworth, H Naito, K Fukagata
Physical Review E | APS Physics | Published : 2014
This paper explains the gain window phenomenon seen in early experimental and computational studies on active, closed-loop control of vortex shedding, whereby shedding is completely suppressed only if the feedback gain lies within some narrow window of stabilizing gains. Using two-dimensional direct numerical simulations and reduced-order modeling techniques, a low-order, linear model of the cylinder wake is formed at a Reynolds number of 60. This model is used to reproduce and to explain the gain window seen in previous studies. It is shown that the gain window is not caused by the destabilization of a higher mode but rather is determined entirely by the behavior of the open-loop unstable m..View full abstract
Awarded by JSPS
Awarded by Grants-in-Aid for Scientific Research
The authors are grateful to Dr. Shinnosuke Obi (Keio University) for fruitful discussion. S.J.I. gratefully acknowledges financial support from the Japan Society for the Promotion of Science (JSPS), who supported him as a Research Fellow during this work. This work was also partly supported through a Grant-in-Aid for Scientific Research (C) (Grant No. 25420129) by the JSPS.