Accepted manuscript
Spectral proper orthogonal decomposition of harmonically forced turbulent flows
Journal of fluid mechanics, Vol.985, A42
04/29/2024
Appears in Aviation Sustainability Center (ASCENT)
Abstract
Many turbulent flows exhibit time-periodic statistics. These include turbomachinery flows, flows with external harmonic forcing and the wakes of bluff bodies. Many existing techniques for identifying turbulent coherent structures, however, assume the statistics are statistically stationary. In this paper, we leverage cyclostationary analysis, an extension of the statistically stationary framework to processes with periodically varying statistics, to generalize the spectral proper orthogonal decomposition (SPOD) to the cyclostationary case. The resulting properties of the cyclostationary SPOD (CS-SPOD for short) are explored, a theoretical connection between CS-SPOD and the harmonic resolvent analysis is provided, simplifications for the low and high forcing frequency limits are discussed, and an efficient algorithm to compute CS-SPOD with SPOD-like cost is presented. We illustrate the utility of CS-SPOD using two example problems: a modified complex linearized Ginzburg–Landau model and a high-Reynolds-number turbulent jet.
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Details
- Title
- Spectral proper orthogonal decomposition of harmonically forced turbulent flows
- Creators
- Liam Heidt - California Institute of TechnologyTim Colonius - California Institute of Technology
- Publication Details
- Journal of fluid mechanics, Vol.985, A42
- Academic Unit
- Aviation Sustainability Center (ASCENT); Noise
- Publisher
- Cambridge University Press
- Number of pages
- 48
- Grants
- 13-C-AJFE-UI-31, Federal Aviation Administration (United States, Washington) - FAA13-C-AJFE-UI-41, Federal Aviation Administration (United States, Washington) - FAA
- Identifiers
- 99901140739201842
- Language
- English
- Resource Type
- Accepted manuscript