Settling of plastic particles in turbulent flow

The global production of plastics is growing exponentially and consequently is the plastic pollution in the environment. At IFP Energies Nouvelles, we develop models that simulate the transport, deposition, and erosion of plastics in the environment. While a specific model for settling is often required, the complex shape of plastics and their intricate interactions with turbulent environments make it very difficult to build. Thanks to the experimental technologies of the ENS Lyon Laboratory, the thesis proposed by IFPEN aims at establishing new settling laws specific to plastic particles, which will help to improve numerical models of the transport and accumulation of plastics in the environment.
What you will do:
•    Laboratory experiments: You will measure the velocity and the trajectories of different plastic particles as well as fluid motion under controlled turbulence conditions, using the state-of-the-art experimental setup developed by B. Laplace during his Ph.D.thesis (Laplace et al. 2023). Several physical parameters (size, shape and density) will be studied to cover the diversity of plastic particles present in the environment. 
•    Statistical analysis of the data: Based on these experimental data, you will develop deterministic and stochastic models to understand the dynamics of different types of particles in interaction with the turbulent fluid, as a function of velocity correlation times and fluid turbulence.
•    Application to environmental scale catchment: Finally, you will work on integrating these models into simulations of the transport and the accumulation of plastics in natural environments at a catchment scale.

Profile sought: Candidates with a solid background on fluid mechanics with a strong motivation for experimental work and an interest in environmental issues. Previous experience in these fields would be an advantage.
Why apply for this IFPEN thesis? Work in a multi-disciplinary team where the research is oriented towards practical applications, with supervisors who are specialists in particles/fluid dynamics or environmental scale simulations.
Cited reference of previous PhD work : Laplace B., J. Vessaire, O. Tolft, M. Bourgoin and R. Volk, 2023, Suspension of Large inertial particles in a turbulent swirling flow. Phys. Rev. Fluids, 8.

Keywords: particles/fluid interaction, settling, micro-plastics, turbulent flow, experimental setting, physical model, numerical model

• Ph.D supervisors    Romain VOLK and Mickaël BOURGOIN, Laboratoire de Physique, ENS Lyon, ORCID 0000-0002-2555-5905 & ORCID 0000-0001-9442-7694
• Doctoral School    ED52 PHAST, Université de Lyon / ENS de Lyon
• IFPEN supervisors    Vanessa TELES, ORCID: 0000-0001-8211-544X & Jean-Lou PIERSON, ORCID: 0000-0002-6231-1424
• PhD locations    ENS Lyon, France and IFPEN, Rueil-Malmaison, France
• Duration and start date    3 years, starting in the fourth quarter 2025 (Novembre 3rd)
• Employer    IFPEN
• Academic requirements    Master in Physics or Fluid Mechanics 
• Language requirements    English level B2 (CEFR)

To apply, please send your cover letter and CV to the IFPEN supervisors indicated here below.