Study of acoustic sources in high subsonic turbulent jet flow
Event details
| Date | 15.03.2012 |
| Hour | 09:30 |
| Speaker | Dr. Dominik Obrist, Institute of Fluid Dynamics, ETH Zurich, Switzerland |
| Location |
MEB10
|
| Category | Conferences - Seminars |
The identification of acoustic sources in high subsonic jet flows at high Reynolds numbers is one of the most pertinent problems in the field of aeroacoustics (sound generated by flows) not least because it is also a problem of high social relevance (e.g. noise emissions from commercial aircraft at take-off). In this seminar, we will present a number of numerical and theoretical methods that have been recently developed in our group and that we are now using for the study of jet aeroacoustics. This includes a high-fidelity solver for the direct noise computation for turbulent jet flows which has been optimized for massively-parallel supercomputers, as well as a far-field solver which is based on a spectral formulation of Lighthill’s acoustic analogy. This spectral formulation has also been used to develop a geometric theory which predicts the directivity of acoustic emissions from wave packet disturbances. We will discuss this theory in detail and will demonstrate how it can be related to modal solutions obtained from the linear stability theory for compressible jet flows. Finally, we will present results from a direct numerical simulation of a turbulent jet at Mach 0.9 and will discuss how the theoretical results for wave packets and modal disturbances may be connected to the actual noise sources of this jet.
Practical information
- Informed public
- Free
Organizer
- Prof. John Botsis