Active closed-loop vortex-induced vibration control of an elastically mounted circular cylinder at low Reynolds number using feedback rotary oscillations

作者：Hasheminejad Seyyed M.^*; Rabiee Amir H.; Bahrami H. R. T.

来源：Acta Mechanica, 2018, 229(1): 231-250.

DOI：10.1007/s00707-017-1960-y

An active rotary oscillation feedback control methodology is adopted to suppress the flow-induced transverse vibration (VIV) of an elastically supported impenetrable circular cylinder in a uniform low Reynolds number flow (). The coupled fluid-structure interaction is replicated by applying the moving mesh technique via a user-defined function (UDF) in the main code of a commercial CFD solver. The closed-loop VIV control action is realized by active forced rotational oscillations of the circular cylinder about its axis based on the feedback signal of the lift coefficient. This prevents the occurrence of resonance by shifting the vortex shedding frequency away from the natural oscillator frequency. Three different active closed-loop proportional controllers are implemented, and their superior performance in cylinder VIV suppression is demonstrated against that of a representative open-loop control system with pre-specified rotational oscillations. It is shown that, in comparison with the open-loop system, the selected closed-loop controller achieves a better cylinder VIV response suppression with a much lower control effort along with considerable reductions in the associated lift/drag coefficients. Furthermore, the closed-loop controller is very effective in a wide range of reduced velocities and does not need to find the "lock-on" forcing frequency for proper de-synchronization. Moreover, the imposed feedback cylinder rotary oscillation is found to considerably affect the spatial characteristics of the wake flow structure by changing the 2S-Coalescent wake pattern (C-2S-mode) of an uncontrolled cylinder into the classical von Karman vortex street (2S-mode), very similar to that of a stationary obstacle. Lastly, when the system is in the fully developed condition, the proportional controller can be complemented by a fuzzy logic inference system for intelligent tuning of gain parameter in order to suppress the impulsive upsurge observed in the cylinder force coefficients of the proportional controller at the start of the control action.

• 出版日期2018-1