CENTRALE LYON - Post doctoral Characterization of the helicopter upper-deck wake and its influence on the tail-shake phenomenon within the Framework of Lattice Boltzmann Simulations)

Research field _____________________________________________
ECL and Laboratory presentation

Founded in 1857, École Centrale de Lyon is one of the top 10 engineering schools in France. It trains more than 3,000 students of 50 different nationalities on its campuses in Écully and Saint-Étienne (ENISE, in-house school): general engineers, specialized engineers, masters and doctoral students. With the Groupe des Écoles Centrale, it has three international locations. The training provided benefits from the excellence of the research carried out in the 6 CNRS-accredited laboratories on its campuses, the 2 international laboratories, the 6 international research networks and the 10 joint laboratories with companies. Its excellent research and high-level teaching have enabled it to establish double degree agreements with prestigious universities and advanced partnerships with numerous companies. With its focus on sobriety, energy, the environment and decarbonization, Centrale Lyon intends to respond to the problems faced by socio-economic players in the major transitions.

The Fluid Mechanics and Acoustics Laboratory (Laboratoire de Mécanique des Fluides et d'Acoustique - LMFA) develops a continuum of research in fluid mechanics and acoustics, from the understanding and the modelling of physical phenomena to applied research, in collaboration with industrial partners and public institutions. Research is organized around three major socio-economic fields: aeronautics and transport, environment and risks, and energy and processes for industry and life.

Research field presentation :

The Lattice Boltzmann (LB) method is gaining strong interest in Computational Fluid Dynamics. While traditional methods rely on a discretization of the Navier-Stokes equations at a macroscopic level, the LB method considers the fluid at a kinetic level. Capturing the dynamics of collections of fluid particles distributed over a lattice is here preferred to solving non-linear PDEs. Processing a simulation in this way has some advantages. The low numerical dissipation allows for an accurate simulation of time-dependent flows, enabling sensitive applications such as aeroacoustics. Furthermore, the high scalability on massively parallel computers can lead to advantageous turn-around times for industrial applications.

The Laboratory of Fluid Mechanics and Acoustics (LMFA, CNRS, Ecole Centrale de Lyon) is seeking a highly qualified candidate for a post-doctoral research fellowship regarding the characterization of the helicopter upper-deck wake and its influence on the tail-shake phenomenon. The numerical simulations will be carried out using ProLB [3], an LB method software developed at LMFA in collaboration with other academic and industrial partners, including Renault, Safran and Airbus.

Description of the activities
Tail-shake can be described as the aerodynamic forcing of structural vibrations, often linked to the presence of complex flow features such as wakes and flow separation and their interaction, whose numerical representation can be challenging for legacy solvers. A detailed experimental characterization of the phenomenon is presented in reference [1]. This project will explore the underlying physics leading to tail-shake through high-fidelity LB numerical simulations, providing greater detail on the phenomenon. The successful candidate will be in charge of setting up, running and analyzing the simulations using ProLB, contrasting results to available experimental data.

This research activity is part of a 3 years-long major project co-funded by the DGAC (French Civil Aviation) and directed by Airbus. The successful candidate will therefore develop his research activity collaboratively with the other academic and industrial partners of the project.

Scientific references:

[1] Desvigne D, Bichon V. Tail-shake risks assessment & mitigation by wind-tunnel tests on air-intake installation on a heavy-weight H/C configuration. The Aeronautical Journal. 2023;127(1313):1192-1218. doi:10.1017/aer.2022.108

[2] PARDO, Miguel Torrente. Compréhension physique et simulation numérique avancée du phénomène hélicoptère Tail-Shake. 2022. Thèse de doctorat. Sorbonne Université. doi: tel-03850713v1

[3] http://www.prolb-cfd.com/research-and-development/. CLIMB: Computational methods with Intensive Multiphysics Boltzmann solver BPIFrance Project No. P3543-24000.

Required skills / qualifications________________________________

Diplomas : PhD in Engineering, Physics, Theoretical and Applied Mechanics, or Applied Mathematics

Experience : Prior Experience in aero-acoustic, turbo-machinery or Lattice Boltzmann method would be an advantage.

Knowledge required: Contributions in the area of scientific computing and Computational Fluid Dynamics.

Operational skills : Physical analysis of fluid dynamics, advanced skills in programming and numerical methods, writing scientific reports and articles, presenting at scientific conferences.

Behavioural skills : Independence, ability to work in a team and adapt to the needs of colleagues, creativity

Work context / environment_______________________________

Attendance at an European  scientific conference is expected.

Recruitment process_______________________________

The recruitment process takes place in two stages, supervised by a recruitment committee, in accordance with Centrale Lyon's OTMR policy.

• Study of the written application:  CV with a cover letter, a summary of recent work and interests,

                one or two letters of reference

• Selection interview: in person or by videoconference

Recruitment timetable: 4 weeks

Selection criteria : excellence