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Showing 1 to 8 of 8 for “"SPOD"”.
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Model order reduction in the frequency domain via spectral proper orthogonal decomposition
… of spectral proper orthogonal decomposition (SPOD), recently revived by Towne et. al. (2018), which results in sets of orthogonal modes, each oscillating at a single frequency, that are said to optimally represent coherent-structures evolving in space and time. However, reduced-order models …
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An experimental investigation of transverse jets in supersonic crossflow
… Spectral Proper Orthogonal Decomposition (SPOD) and Dynamic Mode Decomposition (DMD) were applied to the schlieren data and coherent structures were extracted. The SPOD results show that the modal energy peak frequencies are consistent with the shear layer vortex shedding frequency, and the …
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The Effect of Thermal Non-Uniformity on Coherent Structures in Supersonic Free Jets
… of spectral proper orthogonal decomposition (SPOD) was used to reveal the large-scale, coherent noise producing mechanisms. SPOD results indicate that the thermally non-uniform case showed a decrease in turbulent kinetic energy compared to the uniform case at all frequencies. Coherent …
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Simulation of Flow in a Solid Fuel Ramjet Cavity
… cases, in agreement with the experiments. Using SPOD, these modes were associated with low frequency breathing of the recirculation region at the nozzle throat. Perturbations are localized in the throat region because of the Mach number pressure scaling. These modes do not seem to affect the …
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Propeller Noise Prediction of an Urban Air Mobility Vehicle in Urban Environment
… Two correction strategies—JetEnd and SPODEnd—are tested to mitigate spurious low-frequency end-cap noise. Both yield nearly identical results, differing by less than 2.3 dB, indicating that a single end cap is sufficient for accurate prediction. Theoretical analysis and SPOD-based flow …
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Aeroacoustics Applications to Jets and Rotors
… Spectral Proper Orthogonal Decomposition (SPOD), the study identifies the impact of actuation on the energy distribution across the frequency spectrum. Results demonstrate a measurable reduction in Overall Sound Pressure Level (OASPL), particularly at peak radiation angles, confirming the …
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Stability, LES, and Resolvent Analysis of Thermally Non-uniform Supersonic Jet Noise
For decades noise-induced hearing loss has been a concern of the Department of Defense (DoD). My research investigates noise generation and dispersion in supersonic jets and focuses on the fluid-dynamic regime typical of high-performance turbojet and turbofan engines. The goal of my research is to …
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The Effects of Porous Inert Media in a Self-Excited Thermoacoustic Instability: A Study of Heat Release and Reduced Order Modelling
… a spectral proper orthogonal decomposition (SPOD) method. The energy breakdown showed how PIM reduced and distributed the energy in the flow structures, creating a more stable flow field. Heat release results with velocity information demonstrated the significant coupling mechanisms in the …