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Spectral Analysis Modal Methods (SAMMs) using Non-Time-Resolved PIV

Title: Spectral Analysis Modal Methods (SAMMs) using Non-Time-Resolved PIV.
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Name(s): Zhang, Yang, author
Cattafesta, Louis, author
Ukeiley, Lawrence, author
Type of Resource: text
Genre: Text
Journal Article
Date Issued: 2020-10-10
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: We present spectral analysis modal methods (SAMMs) to perform POD in the frequency domain using non-time-resolved Particle Image Velocity (PIV) data combined with unsteady surface pressure measurements. In particular, time-resolved unsteady surface pressure measurements are synchronized with non time-resolved planar PIV measurements acquired at 15 Hz in a Mach 0.6 cavity flow. Leveraging the spectral linear stochastic estimation (LSE) method of Tinney et al (2006), we first estimate the cross correlations between the velocity eld and the unsteady pressure sensors via sequential time shifts, followed by a Fast Fourier transform to obtain the pressure-velocity cross spectral density matrix. This leads to a linear multiple-input / multiple-output (MIMO) model that determines the optimal transfer functions between the input cavity wall pressure and the output velocity eld. Two variants of SAMMs are developed and applied. The first, termed \SAMM-SPOD", combines the MIMO model with the SPOD algorithm of Towne et al (2018). The second, called \SAMM-RR", adds independent sources and uses a sorted eigendecomposition of the input pressure cross-spectral matrix to enable an efficient reduced rank eigendecomposition of the velocity cross-spectral matrix. In both cases, the resulting rank-1 POD eigenvalues associated with the Rossiter frequencies exhibit very good agreement with those obtained using independent time-resolved PIV measurements. The results demonstrate that SAMMs provide a methodology to perform space-time POD without requiring a high-speed PIV system, while avoiding potential pitfalls associated with traditional time-domain LSE.
Identifier: FSU_libsubv1_scholarship_submission_1607021703_b067bfb4 (IID), 10.1007/s00348-020-03057-8 (DOI)
Keywords: Modal analysis, spectral analysis, cavity oscillations, linear stochastic estimation, POD, SPOD
Publication Note: This is the accepted manuscript. The version of record can be found at https://doi.org/10.1007/s00348-020-03057-8
Preferred Citation: Zhang, Y., Cattafesta, L.N. & Ukeiley, L. Spectral analysis modal methods (SAMMs) using non-time-resolved PIV. Exp Fluids 61, 226 (2020). https://doi.org/10.1007/s00348-020-03057-8
Grant Number: FA9550-17-1-0380
Persistent Link to This Record: http://purl.flvc.org/fsu/fd/FSU_libsubv1_scholarship_submission_1607021703_b067bfb4
Host Institution: FSU
Is Part Of: Experiments in Fluids.
Issue: iss. 226, vol. 61

Choose the citation style.
Zhang, Y., Cattafesta, L., & Ukeiley, L. (2020). Spectral Analysis Modal Methods (SAMMs) using Non-Time-Resolved PIV. Experiments In Fluids. Retrieved from http://purl.flvc.org/fsu/fd/FSU_libsubv1_scholarship_submission_1607021703_b067bfb4