Faites connaître cette offre !
Reference : UPR3346-NADMAA-046
Workplace : POITIERS
Date of publication : Wednesday, July 21, 2021
Scientific Responsible name : Florent MARGNAT - Vincent VALLEAU - Peter JORDAN
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
The CNRS, within the Pprime Institute, on the Futuroscope site, as part of a collaborative research project with the DYNFLUID Laboratory and the Direction Générale de l'Aviation Civile, is recruiting a PhD student who will carry out a thesis of aeroacoustics of wake-airfoil interaction with application to aircraft noise.
In order to comply with increasingly stringent aircraft noise regulations, prediction tools are required from the early stages of aircraft design. Important noise sources at landing are those associated with landing gear and high-lift devices. The interaction between the landing-gear wake and the deployed flap is an aeroacoustic henomenon of particular importance that has received little attention and is poorly understood.
The objective of the PhD is to develop simplified models for the aeroacoustics of wake-airfoil interaction. Experiments will be performed in the anechoic wind tunnel BETI at the Institut Pprime. The experiments will be used to guide the development of a modelling strategy that combines linear mean-flow analysis and a suitable acoustic analogy.
A generic configuration will be considered comprising an upstream obstacle (a simplified representation of a landing gear strut) and a downstream airfoil. The wake of the upstream obstacle will be modelled using linear analysis of the mean flow (global stability / resolvent).
PIV measurements will be used:
- to provide the mean flow for the linear model;
- to identify (using Spectral Proper Orthogonal Decomposition) the dominant flow modes at play in the wake-airfoil interaction;
- to provide flow-mode amplitudes for calibration of the linear model.
Aeroacoustic modelling of the wake-airfoil interaction will rely on an acoustic analogy, where the source field is prescribed by the calibrated modes of the linear mean-flow analysis. Extensive acoustic measurements will be performed in parallel using a microphone array. The acoustic measurements will serve both to validate the model, and to aid in the eventual tuning of model parameters.
The UPR 3346 "Institut Pprime" created on 1 January 2010 depends on the INSIS at the CNRS as an operator; the INP is a secondary institute. A specific agreement recognises the three institutions, CNRS (supervisory body), University of Poitiers and ISAE-ENSMA (partners). The number of staff is around 600: 200 EC, 40 researchers, 100 ITA/IATOS, 180 PhD students and 40 fixed-term contracts.
The research work will be carried out within the D2-FTC, Fluids, Thermal and Combustion department, which corresponds to a continuum ranging from fluid mechanics, inert, anisothermal, reactive, to effects related to physical properties complementary to thermal, combustion and detonation.
Constraints and risks
Short-term travel in France and abroad is to be expected.
Candidates must apply by 17/08/2021 at the latest.
We talk about it on Twitter!