TY - GEN
T1 - Reduced-order models for flow control
T2 - 7th IUTAM Symposium on Laminar-Turbulent Transition
AU - Rowley, Clarence W.
AU - Mezić, Igor
AU - Bagheri, Shervin
AU - Schlatter, Philipp
AU - Henningson, Dan S.
N1 - Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2010
Y1 - 2010
N2 - This paper addresses recent developments in model-reduction techniques applicable to fluid flows. The main goal is to obtain low-order models tractable enough to be used for analysis and design of feedback laws for flow control, while retaining the essential physics. We first give a brief overview of several model reduction techniques, including Proper Orthogonal Decomposition [3], balanced truncation [8, 9], and the related Eigensystem Realization Algorithm [5, 6], and discuss strengths and weaknesses of each approach. We then describe a new method for analyzing nonlinear flows based on spectral analysis of the Koopman operator, a linear operator defined for any nonlinear dynamical system. We show that, for an example of a jet in crossflow, the resulting Koopman modes decouple the dynamics at different timescales more effectively than POD modes, and capture the relevant frequencies more accurately than linear stability analysis.
AB - This paper addresses recent developments in model-reduction techniques applicable to fluid flows. The main goal is to obtain low-order models tractable enough to be used for analysis and design of feedback laws for flow control, while retaining the essential physics. We first give a brief overview of several model reduction techniques, including Proper Orthogonal Decomposition [3], balanced truncation [8, 9], and the related Eigensystem Realization Algorithm [5, 6], and discuss strengths and weaknesses of each approach. We then describe a new method for analyzing nonlinear flows based on spectral analysis of the Koopman operator, a linear operator defined for any nonlinear dynamical system. We show that, for an example of a jet in crossflow, the resulting Koopman modes decouple the dynamics at different timescales more effectively than POD modes, and capture the relevant frequencies more accurately than linear stability analysis.
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U2 - 10.1007/978-90-481-3723-7_6
DO - 10.1007/978-90-481-3723-7_6
M3 - Conference contribution
AN - SCOPUS:84862302607
SN - 9789048137220
T3 - IUTAM Bookseries
SP - 43
EP - 50
BT - 7th IUTAM Symposium on Laminar-Turbulent Transition - Proceedings of the 7th IUTAM Symposium on Laminar-Turbulent Transition
PB - Springer Verlag
Y2 - 23 June 2009 through 26 June 2009
ER -