2026-09-21T11:11:02Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/124604 2026-01-14 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Saxton-Fox, Theresa 2024-05 application/pdf en text Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-05-01 The student, Krithsanvith Manthripragada, accepted the attached license on 2024-05-01 at 15:53. The student, Krithsanvith Manthripragada, submitted this Thesis for approval on 2024-05-01 at 16:10. This Thesis was approved for publication on 2024-05-02 at 16:08. DSpace SAF Submission Ingestion Package generated from Vireo submission #20743 on 2024-09-16 at 00:44:54 Fourier Transforms Fourier Series Skewness Wake Flows Simple, laminar wake flows require many Fourier modes to represent their dynamics, even though they are perfectly periodic with a single period. The spatial form of the Fourier modes alternate between having a maximum value in the center of the wake for odd harmonics and having a zero crossing in the center of the wake for even harmonics of the primary frequency. We demonstrate that the harmonic organization and the alternating shapes of the Fourier modes for simple wakes are direct results of the skewness of the wake, which changes sign at the center of the wake flow. Having a non-zero skewness guarantees that more than one Fourier mode is required to represent the dynamics, even for a perfectly periodic signal, and the spatial variation of the skewness explains the alternating structure of the Fourier modes’ shapes. We demonstrate these relationships through a one-dimensional analysis of how Fourier modes relate to skewness in a model problem and by examining the skewness and Fourier modes of a low Reynolds number flow past a flat plate at an angle of attack of 35 degrees. Text eng https://hdl.handle.net/2142/124604 Copyright 2024 Krithsanvith Manthripragada Relating skewness and Fourier harmonics in low Reynolds number wake flow Manthripragada, Krithsanvith 2024-05-02 M.S. Thesis Theoretical & Applied Mechans University of Illinois at Urbana-Champaign Mechanical Sci & Engineering