ISBN 9783843954082

978-3-8439-5408-2, Reihe Ingenieurwissenschaften

Daniel Kempf
Zonal Computational Aeroacoustics Using a High-Order Discontinuous Galerkin Method

190 Seiten, Dissertation Universität Stuttgart (2023), Hardcover, A5

Zusammenfassung / Abstract

Awareness of the harmful effects of noise emissions is constantly increasing. However, the accurate prediction of complex aeroacoustic effects in numerical simulations is still a challenge. In this thesis, a simulation framework is developed that allows the prediction of complex aeroacoustic effects using zonal computational aeroacoustic methods based on the discontinuous Galerkin scheme. The framework focuses on the efficient zonal simulation of laminar and turbulent flow and the associated mechanisms of noise generation. To demonstrate its capabilities, it is applied to two representative mechanisms: aeroacoustic feedback in a laminar flow and trailing edge noise in a turbulent flow. Aeroacoustic feedback can occur in separated laminar flows and is one cause of tonal noise at a distinct frequency. This effect arises from the interaction of hydrodynamics and acoustics. The second mechanism, trailing edge noise of airfoils, is generated by the scattering of the pressure fluctuations in the turbulent flow at the trailing edge. Therefore, the numerical scheme is required to accurately capture a wide range of turbulent scales to predict the radiated broadband noise. Full-scale, scale-resolved acoustic simulations can capture both effects. However, they are infeasible for practical applications. As a result, zonal simulation methods are developed within this thesis, which allow for reducing the computational cost significantly. To achieve this, the high-fidelity zonal simulation approaches are embedded into the solutions of low-fidelity Reynolds-averaged Navier-Stokes simulations.