Aeroacoustics of planar wakes by means of direct noise computations
This thesis investigates the impact of high-order numerical methods on the accuracy of aerodynamic and aeroacoustic results in Direct Noise Computations (DNC) using the Spectral Element Method (SEM). The analysis begins with the Taylor-Green Vortex (TGV) to demonstrate the fundamentals and benefits...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/422181 |
| Acceso en línea: | https://hdl.handle.net/2117/422181 |
| Access Level: | acceso abierto |
| Palabra clave: | Aerodynamics Aeroacústica Numerical analysis Aeroacoustics Spectral element method Planar wakes Direct noise computation Direct noise simulation High order Aerodinàmica Anàlisi numèrica Àrees temàtiques de la UPC::Física::Termodinàmica |
| Sumario: | This thesis investigates the impact of high-order numerical methods on the accuracy of aerodynamic and aeroacoustic results in Direct Noise Computations (DNC) using the Spectral Element Method (SEM). The analysis begins with the Taylor-Green Vortex (TGV) to demonstrate the fundamentals and benefits of high-order methods. The study then focuses on a NACA0012 airfoil to compute and compare aerodynamic and aeroacoustic results against benchmark data. For the TGV case, four different meshes were evaluated, each undergoing p-refinement, where the evolution of total kinetic energy and enstrophy where evaluated against the baseline solution. In the NACA0012 case, three meshes were tested: the second being an h-refinement of the first, and the third a p-refinement of the second. Aerodynamic parameters such as lift, drag, pressure coefficients, and RMS pressure polar distributions around the airfoil were analyzed. The TGV results indicated that increasing polynomial order reduces errors exponentially, while the simulation time per node and iteration scales linearly. Interestingly, the second-highest polynomial order yielded the best accuracy for three of the four meshes, suggesting that the highest order does not always produce superior results. For the NACA0012 airfoil, the aerodynamic results closely matched benchmark solutions, with the finest meshes delivering the highest accuracy. Additionally, the study confirmed that high-order methods effectively capture aeroacoustic phenomena, with smoother results observed on finer meshes. However, discrepancies in pressure fluctuation propagation led to a detailed mesh analysis, concluding that hp-refinement is essential for optimal aeroacoustic accuracy. In summary, this thesis demonstrates the potential of SEM for accurate and computationally efficient noise prediction, although achieving optimal results requires careful selection of hp-refinement for each specific scenario. |
|---|