PhD student
Laura
MARTIN
LMFA PhD Student
Additional informations
Home laboratory :
LMFA - Thesis directors (s) : Bogey Christophe
- Thesis supervisor(s) : CLAIR Vincent - GABARD Gwénaël - LE BRAS Sophie
- Start date of the thesis : 01/04/2021
- End date of the thesis : 31/03/2024
- Date of defence :
Computational modelling of sound propagation through unsteady flows
The noise generated by models inside a flow can be studied experimentally in open return wind tunnels. For this purpose, the object of interest is placed inside the flow and the microphones used for the acoustic measurements are placed outside the flow. The difference in velocity between the flow and the air at rest generates a layer of turbulence through which the sound must pass before reaching the microphones. Turbulent fluctuations in this layer change the direction of sound propagation, and their movement introduces a Doppler effect. These effects are responsible for a spatial and frequency redistribution of the acoustic energy detected by the microphones. Without taking these effects into account, the exploitation of the results can lead to erroneous conclusions about the position and intensity of the acoustic sources. The objective of this thesis is to study this phenomenon numerically, initially on simplified two-dimensional configurations. A numerical method based on the linearized Euler equations is developed to obtain numerical results of acoustic waves propagating through a turbulent layer. These results will then be analyzed to study in detail the effects of turbulent structures on the spatial and frequency redistribution of acoustic waves. These analyses will be used to support modelling work aimed at recovering the correct characteristics of the flowing sources from the external measurements.
https://celya.universite-lyon.fr/members/laura-martin--260953.kjsp?RH=1524471175521
