Abstract—In this paper a systematic approach for the
nonlinear modeling and feedback control of vorticity behind an
immersed circular cylinder system was developed. In this
technique first a number of control input points over the
cylinder and some measurement points for vorticity past the
cylinder are assigned. A type of nonlinear dynamic model
(namely a Hammerstein-Wiener (HW) model) of the flow field
is estimated via system identification techniques using
measurement data obtained from a chirp input function. Once
the dynamical model of the system is estimated, a controller for
the linear block of the HW model is designed using internal
model control method, and this controller is then mapped to the
HW model by reversing the input/output nonlinearity
functions. The procedure described is implemented and tested
numerically in MATLAB and CFD computations performed on
the closed-loop system show that the controller is capable of
achieving significant reduction in the vorticity levels past the
cylinder.
Index Terms—Flow past a circular cylinder, nonlinear
dynamical modeling and control, system identification,
hammerstein-wiener method, vorticity control.
H. D. Karaca and C. Kasnakoglu are with the Department of Electrical
and Electronics Engineering, TOBB ETU, 06560, Ankara, Turkey (e-mail:
hdkaraca@gmail.com, kasnakoglu@etu.edu.tr).
G. D. Ozen is with the Department of Physics in METU, Ankara, Turkey
(e-mail: gd.ozen@gmail.com).
[PDF]
Cite:H. Deniz Karaca, G. Deniz Özen, and Coşku Kasnakoğlu, "A Nonlinear Dynamical Modeling and Control Method for the Vorticity Control of the Flow past a Circular Cylinder," International Journal of Materials, Mechanics and Manufacturing vol. 1, no. 4, pp. 324-346, 2013.
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