A Novel Dynamical Systems View of Wall Bounded Turbulence at University of Sheffield

February 26, 2024

Job Description

The project combines state-of-the-art advanced mathematical tools and numerical simulations to better understand, model and control wall-bounded turbulent flows for greener transportation and energy.

Working under the supervision of Dr Elena Marensi, the successful candidate will join a vibrant team of researchers within the Sheffield Fluid Mechanics Group as well as benefiting from close collaborations with world-leading groups in Europe. The project aims at providing PhD students with top-quality, challenging training at the forefront of research into wall-bounded turbulent flows.

About the project: Turbulence is the primary cause of frictional losses in transport processes (vehicular transport, distribution pipelines) and the main contributor to drag increase in wall-bounded flows. Estimates show that the energy wasted in overcoming this drag accounts for 25% of all UK carbon emissions.  Even a few percentage drag reduction would therefore contribute to a more energy-efficient global transportation network, leading to huge economic savings and improved air quality. Surprisingly, recent experiments and simulations have shown the possibility to completely suppress turbulence (and thus achieve the maximum possible drag reduction)  by momentarily making the flow even more turbulent. On a theoretical basis though, the reason why the above method works is still a mystery. This project thus aims at investigating relaminarisation events and flow control strategy due to energetic impulses by exploring a novel dynamical systems picture of wall-bounded turbulence. The problem will be tackled with a combination of state-of-the-art advanced mathematical tools and numerical simulations, and the new understanding proposed here will be used to develop novel control strategies (based on the same principle) that are applicable in practice.

During this project, you will gain significant experience in:

  • Computational fluid mechanics using in-house high-fidelity numerical software and high-performance computing
  • Turbulence (modelling and control) and transition to turbulence
  • Dynamical system theory, flow instabilities and chaos
  • Analysing large data-sets and developing codes for data processing
  • Working in a multidisciplinary/international environment

If you are interested in applying and wish to discuss any details of the project informally, please contact Dr Elena Marensi at e.marensi@sheffield.ac.uk.

About the Department: PhD studentships at Sheffield provide students with the opportunity to study within one of the UK’s leading Mechanical Engineering departments, internationally renowned for long-standing success in research which looks at some of today’s most challenging issues and develops new innovations to solve them. The expertise of our staff covers a wide range of specialist areas and our mission is to carry out research in fundamental science through to practical industrial applications.

Requirements:

Education A very good 4-year degree or master’s degree in Mechanical, Aeronautical, Marine, Civil, Chemical Engineering, Applied Mathematics or Physics  (at least a UK 2:1 honours degree, or its international equivalent)

Knowledge, skills Strong background in applied mathematics/physics/fluid mechanics and good programming skills (e.g. Fortran, Python/Matlab). Any knowledge in wall-bounded turbulence and dynamical system theory is a plus. Desirable: final-year project on a fluid mechanics problem.

Other requirements We are looking for a dedicated, dynamic and self-motivated individual with a strong passion for fluid mechanics research. Excellent communication and scientific writing skills are also required as well as a strong ability to work both individually and in a team.


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