PhD student
Igor
KUREK
LMFA PhD Student
Additional informations
Home laboratory :
LMFA - Thesis directors (s) : Christophe Bailly
- Thesis supervisor(s) : Thomas Castelain et Pierre Lecomte
- Start date of the thesis : 01/10/2020
- End date of the thesis : 30/09/2023
- Date of defence : 19/01/2024
High-frequency characterization of temperature fluctuations in high-Reynolds compressible slightly-heated jets
In numerous industrial applications of high speed-jets, e.g. aircraft engines, thermal effects influence the flow development and subsequent flow characteristics such as its acoustic signature. Measurements of turbulent temperature fluctuations in high-speed jets coupled with acoustic characterization are seldom. It is at first due to the ineherent complexity of flow temperature field measurements. In-flow total temperature probe faces limitations due to compressibility effects and thermal lag. Most of the optical methods readily available at Lab scale are particule-related techniques focused on the determination of velocity field components (PIV, LDV), whereas other advanced optical methods (e.g. molecular tagging) would be applied in an anechoic environment with great practical difficulties. The aim of the present PhD work is to characterize the effect of high-speed jet temperature on the jet development and on the acoustic source properties (location, intensity). To reach this objective, experiments will be performed in an anechoic room coupled with high-speed wind-tunnel. Subsonic and underexpanded jets will be considered. Building upon recent developments in the Lab concerning in one hand the development of an optical method for density fluctuations based on Rayleigh scattering, and in the other hand compact-probes thermometry with in-house developed Constant Voltage Thermometer, the first step will consist in measurements in moderate-speed jets where compressibility effects are sufficiently small to allow for a comparison between the results obtained with these two methods. In a second time, the development of in-line spectrography of the scattered-light at high frequency will allow for the determination of the spectral properties of the local temperature in the flow. This step is necessary for a better identification of shock noise sources for instance,4 because it provides access to correlations between temperature, velocity and density within the flow.
https://celya.universite-lyon.fr/members/igor-kurek--260936.kjsp?RH=1524471175521
