A reduced-order model of three-dimensional unsteady flow in a cavity based on the resolvent operator

F. Gomez, H. M. Blackburn, M. Rudman, A. S. Sharma, B. J. McKeon

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30 Citations (Scopus)

Abstract

A novel reduced-order model for time-varying nonlinear flows arising from a resolvent decomposition based on the time-mean flow is proposed. The inputs required for the model are the mean-flow field and a small set of velocity time-series data obtained at isolated measurement points, which are used to fix relevant frequencies, amplitudes and phases of a limited number of resolvent modes that, together with the mean flow, constitute the reduced-order model. The technique is applied to derive a model for the unsteady three-dimensional flow in a lid-driven cavity at a Reynolds number of 1200 that is based on the two-dimensional mean flow, three resolvent modes selected at the most active spanwise wave number, and either one or two velocity probe signals. The least-squares full-field error of the reconstructed velocity obtained using the model and two point velocity probes is of the order of 5 % of the lid velocity, and the dynamical behaviour of the reconstructed flow is qualitatively similar to that of the complete flow.

Original languageEnglish
Pages (from-to)R2-1-R2-14
Number of pages14
JournalJournal of Fluid Mechanics
Volume798
DOIs
Publication statusPublished - 2016

Keywords

  • Low-dimensional models
  • Nonlinear dynamical systems

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