ERC Advanced Grant on "The Physics of Fluids group works on a variety of aspects in Fluid Mechanics. The focus of our work is the fundamental understanding the phenomena of the physics of fluids. Present research areas include turbulence and multiphase flow, micro- and nanofluidics, biomedical flow, and granular flow. Both fundamental science and more applied science – then often in close collaboration with industrial partners - is done in the group and both experimental, theoretical, and numerical methods are used. The group presently has 6 scientific staff members, 5 part-time professors, 4 supporting technicians, and typically 10 postdocs, 35 PhD students, and 10–15 master students.

Our research is embedded in the Max Planck Center Twente for Complex Fluid Dynamics and the J.M. Burgers Research Center for Fluid Mechanics (JMBC) and in the MESA+ and MIRA Institutes in Twente. The group receives external research funds from e.g. ERC, NWO, EU, and several industrial partners.

Presently, there are several vacancies in the context of Detlef Lohse’s ERC Advanced Grant on "Diffusive Droplet Dynamics in multicomponent fluid systems". This project has been triggered by the challenges in Liquid-liquid extraction – the transfer of a solute from one solvent to another – which is one of the core processes in chemical technology and analysis. The current challenge is to miniaturise the extraction process of the analyte and to optimize the extraction recovery and pre-concentration factor. In lack of a priori calculations, this is presently often done by trial-and-error. However, to be able to control and optimize the extraction processes, it is crucial to quantitatively understand the diffusive droplet dynamics in multicomponent fluid systems. This is essential and urgently needed not only for modern liquid-liquid extraction processes for diagnostics and microanalysis, for droplet microfluidics, or in the paint & coating industry, but on larger scales also in the remediation industry, in chemical technology, or in food processing. These applications of droplets governed by diffusion include cases of immersed droplets in the bulk and on a surface, single and multicomponent droplets and solvents, growing or shrinking droplets, and cases with high droplet number density. Unfortunately, in spite of their relevance, multiphase and multicomponent fluid systems with relevant diffusive droplet dynamics are poorly understood.

The objective of this project is a true scientific breakthrough: the work we propose will fill this gap and come to a quantitative understanding of diffusive droplet dynamics and thus to illuminate the fundamental fluid dynamics of diffusive processes of immersed (multicomponent) (surface) droplets on multiple scales. To achieve this objective, we want to perform a number of key controlled experiments and numerical simulations for idealized setups on 9 orders of magnitude in length scale, allowing for a one-to-one comparison between experiments and numerics/theory. We want to bridge the gap from modern fluid dynamics to process-technology and colloidal & interfacial science, from nano/microscopic and purely diffusively governed droplets to macroscopic ones and from single droplets to multiple and multi-component droplets, to arrive at multiscale high-precision chemical engineering for droplets.

The open positions include:

• 2 PhD positions for experiments on surface and bulk droplets, applying various optical imaging techniques
• 1 PhD position for large-scale experiments on dispersed multiphase flow
• 1 PhD position for numerical simulations employing finite difference methods and immersed boundary methods
• 1 PhD position for numerical simulations employing Molecular Dynamics and Volume of Fluid methods.

3 Postdoc positions for applying optical techniques, in particular confocal, fluorescence, digital holographic microscopy, high-speed imaging, AFM, and synchrotron tomography.

• You hold a master degree in physics, fluid mechanics, mechanical or chemical engineering or applied mathematics.

• You have good expertise in one or more of the following research areas: physics, fluid mechanics, mechanical or chemical engineering.

• You are driven to do good research in the area of the project.

• You are fluent in English.

We offer a very challenging fulltime position in an inspiring multidisciplinary and international environment. The university offers a dynamic ecosystem with enthusiastic colleagues in which internationalization is an important part of the strategic agenda.

• For the PhD positions the gross monthly salary starts with € 2222,- in the first year and increases to € 2840,- in the fourth year of your employment;
• For the postdoc positions your gross monthly salary depends on experience and qualifications and ranges from € 3111.- to € 4084.-;
• A holiday allowance of 8% of the gross annual salary and a year-end bonus of 8.3%;
• A solid pension scheme;
• Minimum of 29 holidays in case of full-time employment;
• Professional and personal development programs;

Information and application
Application of driven students and postdocs from physics, fluid mechanics, mechanical or chemical engineering with the appropriate background should be sent to d.lohse@utwente.nl before 15 November 2017.

The University of Twente. We stand for life sciences and technology. High tech and human touch. Education and research that matter. New technology which drives change, innovation and progress in society. The University of Twente is the only campus university in the Netherlands; divided over six faculties we provide more than fifty educational programmes. The University of Twente has a strong focus on personal development and talented researchers are given scope for carrying out pioneering research.

Within the TNW Faculty (Faculty of Science & Technology) of the University of Twente some 700 staff members and 2000 students are involved in training and research on the interface of chemical technology, applied physics and biomedical technology. Fields of application include sustainable energy, process technology and materials science, nanotechnology and technical medicine. Research, which enjoys a high profile both at home and internationally, has been accommodated in the multidisciplinary research institutes MESA+ and MIRA. The faculty works together intensively with industrial partners and researchers in the Netherlands and abroad and conducts extensive research for external commissioning parties and funders.