ISBN 978-3-8439-0490-2

978-3-8439-0490-2, Reihe Ingenieurwissenschaften

Mohammad Kamruzzaman
Study of Turbulence Anisotropy and Its Impact on Flow Induced Noise Emission

211 Seiten, Dissertation Universität Stuttgart (2011), Hardcover, A5

Zusammenfassung / Abstract

This doctoral thesis focuses on the modelling and analysis of the turbulence anisotropy flow structure and its impact on the broadband turbulent boundary-layer induced trailing-edge interaction (TBL-TE) noise prediction. This type of noise represents an important issue for the aeroacoustic research, as it occurs in many technical situations, such as wind turbine noise, airframe noise (flow over sharp lifting surfaces), turbo-machinery noise (flow over a turbine or compressor blade) etc. The main source mechanism of this noise is boundary-layer turbulence, which is inhomogeneous and anisotropic in character and very difficult to model numerically. The objective of the current study is twofold: firstly, to better understand the process, by which anisotropic turbulent boundary-layer (TBL) flow produces wall pressure fluctuations (WPFs), and secondly, the development of a method to model anisotropic turbulence properties from standard RANS results. The approach was to study the statistics of both the wall pressure field and velocity field for a non-equilibrium anisotropic airfoil boundary-layer (BL), and then to model turbulent structures in the flow that contribute to the source terms of the wall pressure field. Detailed velocity, wall pressure and far-field noise measurements were analysed to provide a basis of comparison for the numerical flow and noise prediction results.