Optimization of the wake oscillator for transversal VIV.

Kurushina, Victoria; Postnikov, Andrey; Franzini, Guilherme Rosa; Pavlovskaia, Ekaterina

Abstract

Vibrations of slender structures associated with the external flow present a design challenge for the energy production systems placed in the marine environment. The current study explores the accuracy of the semi-empirical wake oscillator models for vortex-induced vibrations (VIV) based on the optimization of (a) the damping term and (b) empirical coefficients in the fluid equation. This work investigates the effect of ten fluid damping variations, from the classic van der Pol to more sophisticated fifth-order terms, and prediction of the simplified case of the VIV of transversally oscillating rigid structures provides an opportunity for an extended, comprehensive comparison of the performance of tuned models. A constrained nonlinear minimization algorithm in MATLAB is applied to calibrate considered models using the published experimental data, and the weighted objective function is formulated for three different mass ratios. Comparison with several sources of published experimental data for cross-flow oscillations confirms the model accuracy in the mass ratio range. The study indicates the advantageous performance of the models tuned with the medium mass ratio data and highlights some advantages of the Krenk–Nielsen wake oscillator.

Citation

KURUSHINA, V., POSTNIKOV, A., FRANZINI, G.R. and PAVLOVSKAIA, E. 2022. Optimization of the wake oscillator for transversal VIV. Journal of marine science and engineering [online], 10(2), article number 293. Available from: https://doi.org/10.3390/jmse10020293

• Journal Article Type: Article
• Acceptance Date: Jan 28, 2022
• Online Publication Date: Feb 20, 2022
• Publication Date: Feb 28, 2022
• Deposit Date: Feb 13, 2024
• Publicly Available Date: Feb 27, 2024
• Journal: Journal of marine science and engineering
• Electronic ISSN: 2077-1312
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 2
• Article Number: 293
• DOI: https://doi.org/10.3390/jmse10020293
• Keywords: Vortex-induced vibrations; VIV; Wake oscillator; Phenomenological model; Rigid structures; Transversal oscillations
• Public URL: https://rgu-repository.worktribe.com/output/2166750