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Showing 1 to 7 of 7 for “"ffowcs williams-hawkings"”.
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Adaptive mesh refinement for computational aeroacoustics
… sound directivity is estimated by solving the Ffowcs Williams-Hawkings equation. The overall results demonstrate the accuracy and the efficiency of the presented AMR method, but also reveal some limitations. The possible methods to avoid these limitations are given at the end of this thesis.
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Prediction of Tonal Acoustic Radiation Due to Feedback-Loop Resonant Interactions in Transitional Airfoils
… the two dimensional formulation of the Ffowcs Williams - Hawkings (FW-H) equation in frequency, domain is reviewed and then the method is implemented to be used for extending the numerical simulations to far-field evaluations. In order to verify the implemented methods, monopole source …
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High Fidelity Open Rotor Noise Prediction
… focuses on one set of methods based on the Ffowcs Williams-Hawkings (\fwh) equation. This equation is considered to be the most realistic description of aeroacoustic noise generation, as it is a direct rearrangement of the Navier-Stokes equations. The \fwh\ equation is difficult to solve for …
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Implementing and testing a panel-based method for modeling acoustic scattering from CFD input
… CFD plus surface integral methods such as the Ffowcs-Williams Hawkings method, the scattered sound field is complicated by its dependence on the geometry of the scattering surface---the aircraft carrier deck, aircraft control surfaces and other nearby structures.</p> <p>In this work, a …
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Stability, LES, and Resolvent Analysis of Thermally Non-uniform Supersonic Jet Noise
… capture the viscous sublayer at the nozzle. The Ffowcs Williams-Hawkings (FW-H) method is used for far-field noise predictions for all cases. Three-dimensionality is studied to investigate how injection in the shear layer acts to create a rotational inviscid core and affects the mixing of the …
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Prediction & Active Control of Multi-Rotor Noise
… Far-field sound predictions were performed using Ffowcs-Williams-Hawkings formulation. The two-propeller results in hovering are compared with that of the single propeller. This enabled us to identify the aerodynamic changes resulting from the proximity of the two propellers to each other and to …
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Aeroacoustics Applications to Jets and Rotors
<p>Aeroacoustics plays a critical role in the advancement of propulsion technologies for both conventional and emerging aerial systems. This dissertation investigates two key topics: noise suppression in supersonic rectangular jets and rotor noise characterization in hover and ground effect. Using …