Data-driven insights into fluid-structure association and energy quantification

ORAL

Abstract

The linear-time-invariance notion to the Koopman Analysis (Part I - Li et al., 2022, Phys. Fluids 34(12) 125136; Part II - Li et al., 2023, J. Fluid Mech. 959, A15) and its derived augmented algorithm (Fu et al., 2023, Phys. Fluids 35(2) 025112) are recent advances in fluid mechanics, addressing the challenge of correlating nonlinear excitation and response in fluid-structure interactions (FSI). Continuing the serial research, this work presents a data-driven, Koopman-inspired approach integrated with the "Proper Orthogonal Decomposition-Dynamic Mode Decomposition-Discrete Fourier Transform Augmented Analysis (POD-DMD-DFT)" to decouple nonlinear FSI. This innovative approach first isolates energy-wise and evolution-wise significant nonlinear flow features, subsequently establishing cause-and-effect correspondences between these flow features and structure surface pressure. Dynamic visualizations of in-sync fluid-structure-coupled Koopman modes is then implemented for phenomenological analysis. Finally, FSI energy transfers is statistically quantified via spatiotemporal contribution and probability density distributions. Demonstrated based on high-fidelity direct numerical simulation and large eddy simulation of flow over typical rigid obstacles, our method offers insightful descriptions and interpretations of phenomena occurring in the flow and on the boundary (walls) of an FSI domain, and readily applies to various engineering problems given its data-driven nature.

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Publication: Published:
[1] C.Y. Li, Z. Chen, X. Lin, A.U. Weerasuriya, X. Zhang, Y. Fu, T.K.T. Tse, The linear-time-invariance notion to the Koopman analysis: The architecture, pedagogical rendering, and fluid–structure association, Physics of Fluids 34(12), 125136 (2022).
[2] C.Y. Li, Z. Chen, T.K.T. Tse, A.U. Weerasuriya, X. Zhang, Y. Fu, X. Lin, The linear-time-invariance notion of the Koopman analysis. Part 2. Dynamic Koopman modes, physics interpretations and phenomenological analysis of the prism wake, Journal of Fluid Mechanics 959, A15 (2023).
[3] Y. Fu, X. Lin, L. Li, Q. Chu, H. Liu, X. Zheng, C.-H. Liu, Z. Chen, C. Lin, T.K.T. Tse, C.Y. Li, A POD-DMD augmented procedure to isolating dominant flow field features in a street canyon, Physics of Fluids 35(2), 025112 (2023).

Submitted:
[1] C.Y. Li, L. Zhang, S. Li, X. Zhang, Z. Chen, Y. Fu, X. Lin, D.Z. Peng, Y. Wang, B. Zhang, L. Zhou, Y. Wang, H. Liu, A.U. Weerasuriya, T.K.T. Tse, Q. Yang, Linear-time invariance notion to Koopman analysis. Part 3. Data-driven quantification of fluid-structure energy transfers, Physics of Fluids (2024)
[2] X. Lin, D.Z. Peng, T.K.T. Tse, C.Y. Li, Y. Wang, POD-DMD-DFT Augmented Analysis: identify and visualize energy-wise and evolution-wise significant nonlinear flow features, Nonlinear Dynamics (2024)

Presenters

  • Cruz Y. Li

    School of Civil Engineering, Chongqing University

Authors

  • Cruz Y. Li

    School of Civil Engineering, Chongqing University

  • Yunlong Wang

    School of Civil Engineering, Liaoning Technical University

  • Shuang Wu

    School of Civil Engineering, Liaoning Technical University

  • Xisheng Lin

    Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology

  • Tim K.T. Tse

    Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology