PhD on critical transitions in rotating turbulence

Are you intrigued by coherent structure formation in geophysically and astrophysically inspired flows? Are you passionate about working with unique experimental infrastructure? Are you interested in studying transitions between turbulent states?

Information
An intriguing effect of constraining a turbulent flow, e.g. by adding rotation, is that the energy cascade may change: some part of the energy may be transferred to larger scales, forming large-scale structures (vortices or jets) that are essentially two-dimensional. There is evidence that this change is sharp: the transition between pure downscale energy transfer and (partial) upscale transfer resembles a critical transition. Can we understand, model and predict this transition? How universal is this transition with respect to the flow forcing mechanism (thermal convection or mechanical forcing)? Large-scale structures are found in many constrained turbulent flow systems at planetary scales. Knowledge of the transition will lead to a better understanding of these flows, with predictive power for similar flow problems that are harder to diagnose. For example, the structure of the flow in Earth’s liquid-metal outer core is decisive for the generation of the magnetic field that shields us from harmful radiation. The application also extends to planetary atmospheres, including that of our own Earth.

The goal of this PhD project is to experimentally explore the transition to large-scale structure formation in rotationally constrained turbulent convection. You will use an experimental setup unique in the world for the study of turbulent rotating convection. You will use temperature measurements and optical velocimetry (particle image velocimetry, 3D particle tracking velocimetry) for flow diagnostics, allowing us to assess the flow structuring. Using stepwise changes in the experiment settings, you will explore the transition behavior and possibly related hysteresis. Can we understand and predict the transitions?

This PhD position is part of the project “Universal critical transitions in constrained turbulence”, in which this topic is studied both numerically and experimentally. Additional directions to be explored are: influence of lateral confinement (enclosed vs horizontally periodic domains), use of different forcing mechanisms, and investigation of energy transfers in the saturated final vortex state. The final goal is the development of a predictive model for the transition: are the properties universal?

You will become a member of the Fluids and Flows group, consisting of ~35 researchers (PhD students, postdocs and staff). The group covers a wide range of fluid flow topics organized into four main research lines: Turbulence, Environmental Fluid Mechanics, Multiphase and Complex Fluids and Micro- and Nanohydrodynamics.

Besides research you will also contribute to education within our group and the Department of Applied Physics. You will guide and supervise BSc and MSc students in their research projects. Other assistance in education, e.g. in BSc-level courses, is usually limited to around 5% of your contract time. Note that if you are specifically interested in teaching and education, there is the option for a 1-year extension of your PhD studentship. Your teaching and education tasks will then amount to a time equivalent of more than a full contract year during your PhD project. Please express your interest to the vacancy holder/supervisor in charge.

Do you recognize yourself in this profile and would you like to know more? Please contact the hiring manager, dr.ir. Rudie Kunnen, r.p.j.kunnen@tue.nl.

Visit our website for more information about the application process or the conditions of employment. You can also contact HRServices.flux@tue.nl.

Are you inspired and would like to know more about working at TU/e? Please visit our career page.

We invite you to submit a complete application by using the apply button. The application should include a:

• Cover letter in which you describe your motivation and qualifications for the position.
• Curriculum vitae, including a list of your publications and the contact information of three references.
• Brief description of your MSc thesis.

We look forward to receiving your application and will screen it as soon as possible. The vacancy will remain open until the position is filled.