EPFL, the Swiss Federal Institute of Technology in Lausanne, is one of the most dynamic university campuses in Europe and ranks among the top 20 universities worldwide. The EPFL employs more than 6,500 people supporting the three main missions of the institutions: education, research and innovation. The EPFL campus offers an exceptional working environment at the heart of a community of more than 17,000 people, including over 12,500 students and 4,000 researchers from more than 120 different countries.

PhD position: Analysis and modelling of 3D bluff body wakes

Mission

We are offering a challenging position as a full-time (100%) PhD Student at the School of Engineering at EPFL, Lausanne. Our laboratory (LFMI) is focused on the study of hydrodynamic instability applied to separated flows, coaxial jets and droplet formation, as well as droplet-based microfluidics. You will be working on a SNSF-funded project whose goal is to analyze and model 3D bluff-body wakes.

Fluid flows past bluff bodies arise in many natural and engineering situations: (i) ground vehicles, crucially in need of improved aerodynamics in order to reduce emissions of CO2, in order to mitigate climate change; (ii) civil engineering, where unsteady vortex shedding past slender structures induce mechanical fatigue and failure; (iii) energy-harvesting systems exploiting fluid-structure interaction in natural streams like rivers/oceans to produce electricity; and (iv) freely falling objects like tree seeds (relevant to biological population) and industrial particles (in food and chemical processes). Decades of extensive studies on bluff body wakes have yielded results of great significance on flow stability, reduced-order models, and flow control. Yet, unexplored areas still exist in the laminar and turbulent regimes alike.

 

The objective of these two SNSF-funded PhD theses is to combine theoretical and numerical tools to address some of the gaps existing in the understanding and modelling of 3D bluff body wakes. A particular focus will be put on wakes exhibiting bistability (e.g. 3D rectangular prisms and Ahmed bodies) or multistability (e.g. axisymmetric bodies) related to planar or azimuthal symmetry breaking, and induced either by stochastic forcing in the laminar regime or by turbulent fluctuations in the turbulent regime.

Some of the topics of interest include: (i) study the effect of misalignment (yaw and pitch) and ground proximity on the laminar flow past Ahmed bodies, using linear and weakly nonlinear stability analysis; (ii) develop amplitude equations for stochastically forced laminar flows near symmetry-breaking bifurcations; (iv) develop reduced-order models especially designed for stochastic flows with symmetries; (iv) develop amplitude equations for turbulent wakes.

Main duties and responsibilities

As a PhD Student, you will be expected to:

 

  • Have full responsibility for your own dissertation
  • Derive equation-based models
  • Design, implement and execute numerical simulations
  • Analyze and interpret results
  • Write scientific articles for publication in peer-reviewed journals
  • Present at international conferences
  • Supervise student projects and basic administrative support

Profile

  • A M.Sc. degree in the fields of Engineering, Physics or Applied Maths
  • Good communication skills and willingness to work as part of a team
  • Enthusiasm, scientific curiosity, eager to learn, good organizational skills, rigor
  • High level of motivation for academic research work in general, and specfically for theoretical/numerical aspects of fluid mechanics
  • Experience with flow stability, dynamical systems, weakly nonlinear analysis, reduced-order modelling, stochastic analysis, or CFD
  • Fluency in English

We offer

  • 4 years to complete your PhD with a competitive remuneration
  • You will be part of the EDME doctoral program
  • An opportunity to develop a scientific career in fluid mechanics
  • A world-class research and training environment with access to state-of-the-art research facilities
  • A multi-cultural and stimulating work environment
  • Term of employment: 1-year fixed-term contract (CDD), renewable for 4 years

Informations

Only applications submitted through the online platform are considered. Your application should contain:

 

  • Motivation Letter
  • Detailed CV
  • Contact information
  • At least 2 references willing to write a recommendation letter. Letters of recommendation should be sent back by the same deadline

 

CDD for 1 year, renewable for 4 years

 

For more information, please contact: edouard.boujo@epfl.ch

 

If you are successful, you will need to enroll in one of the EPFL doctoral school programs. Please check this page for additional information. Please note that this is a separate application process necessary to be eligible to complete your PhD at EPFL.