Noise Sources in Turbulent Shear Flows
- Roberto Camussi (Università di Roma Tre, Roma, Italy)
- 4 lectures on: Boundary layer noise. The structure and relevant features of turbulent boundary layers. Mechanism of noise generation in a turbulent boundary layer. Surface-pressure fluctuations induced by boundary-layer flow and relevant predicting models. Spectral features of wall pressure fluctuations in case of separation and effects of roughness and compressibility. Recent advances on wall pressure data analysis.
- Tim Colonius (California Institute of Technology, Pasadena, CA, USA)
- 5 lectures on: Computational Aeroacoustics.These lectures focus on the development and application of high-fidelity computational approaches to sound generation by turbulent flows. The material will include discretization of the compressible Navier-Stokes equations and Fourier Analysis of discretization errors. Applications to jet noise, airframe noise, and cavity tones will be discussed.
- Avraham Hirschberg (Eindhoven University of Technology, Eindhoven, The Netherlands)
- 6 lectures on: Introduction to aeroacoustics and Self-sustained oscillations of internal flows. Using the analogy of Lighthill, the basic concepts of acoustics and aeroacoustics will be introduced. The instability of internal flows due to coupling between shear layer instability and acoustic resonance will be discussed. Various industrial applications will be considered such as the role of closed side branches and diffusers.
- Peter Jordan (CNRS, UPR 3346, Poitiers, France)
- 6 lectures on: Experimental aeroacoustics and noise source identification.The lectures will include a brief overview of aeroacoustic theory, as well as a survey of modern data-processing techniques and the information which these have provided. The lectures will be structured so as to give a sense of where we currently stand in terms of our understanding of jet noise.
- Philip J. Morris (The Pennsylvania State University, University Park, PA, USA)
- 7 lectures on: Jet noise: fundamentals and modeling. Following an introduction on the application of the acoustic analogy to jet noise, simple scaling laws are derived. The effects of the jet mean flow on the noise radiation are described including methods of prediction. The identification of noise sources in jets and numerical/experimental observations of jet noise are described.
- Michel Roger (Ecole Centrale de Lyon, Ecully, France)
- 7 lectures on: Noise from moving surfaces, such as airfoils (turbulence-interaction noise and trailing-edge noise) or rotating blades. Duct acoustics. Mechanisms of generation of noise generated by rigid moving surfaces interacting with flows are described. Basic principles are discussed together with examples including rotating blades and applications to open rotors. Duct acoustics is described mainly considering simplified geometries in order to emphasise basic physical mechanisms.