English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Modal decompositions such as proper orthogonal decomposition (POD), dynamicmode decomposition (DMD) and their variants are regularly used to educephysical mechanisms of nonlinear flow phenomena that cannot be easilyunderstood through direct inspection. In fluid-structure interaction (FSI)systems, fluid motion is coupled to vibration and/or deformation of an immersedstructure. Despite this coupling, data analysis is often performed using onlyfluid or structure variables, rather than incorporating both. This approachdoes not provide information about the manner in which fluid and structuremodes are correlated. We present a framework for performing POD and DMD wherethe fluid and structure are treated together. As part of this framework, weintroduce a physically meaningful norm for FSI systems. We first use thiscombined fluid-structure formulation to identify correlated flow features andstructural motions in limit-cycle flag flapping. We then investigate thetransition from limit-cycle flapping to chaotic flapping, which can beinitiated by increasing the flag mass. Our modal decomposition reveals that atthe onset of chaos, the dominant flapping motion increases in amplitude andleads to a bluff-body wake instability. This new bluff-body mode interactstriadically with the dominant flapping motion to produce flapping at thenon-integer harmonic frequencies previously reported by Connell & Yue (2007).While our formulation is presented for POD and DMD, there are naturalextensions to other data-analysis techniques.

Modal decomposition of fluid-structure interaction with application to flag flapping