PhD on critical transitions in rotating turbulence

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 turbulence. You will design a novel experimental setup incorporating both thermal and mechanical flow forcing. You will apply 3D particle tracking velocimetry for volumetric flow diagnostics, allowing us to quantify the energy transfers among spatial scales. You will evaluate the transition properties for the two forcing mechanisms. Is there universal behavior?

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), description of hysteresis in the transition, 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.

A meaningful job in a dynamic and ambitious university, in an interdisciplinary setting and within an international network. You will work on a beautiful, green campus within walking distance of the central train station. In addition, we offer you:

• Full-time employment for four years, with an intermediate evaluation (go/no-go) after nine months. You will spend 10% of your employment on teaching tasks.
• Salary and benefits (such as a pension scheme, paid pregnancy and maternity leave, partially paid parental leave) in accordance with the Collective Labour Agreement for Dutch Universities, scale P (min. €2,872 max. €3,670).
• A year-end bonus of 8.3% and annual vacation pay of 8%.
• High-quality training programs and other support to grow into a self-aware, autonomous scientific researcher. At TU/e we challenge you to take charge of your own learning process.
• An excellent technical infrastructure, on-campus children's day care and sports facilities.
• An allowance for commuting, working from home and internet costs.
• A Staff Immigration Team and a tax compensation scheme (the 30% facility) for international candidates.