PhD Positions Experimental Fluid Mechanics: Inertial Dense Suspensions

Curious about how dense particle flows defy the usual rules of laminar and turbulent motion? Join our ERC-funded project and uncover the physics behind inertial dense suspensions, flows that shape technologies from energy storage to biomedical systems.

Job description

Inertial Dense Suspensions (IDeS) are common in nature and industry, with examples ranging from blood flow and recycling to waste slurry transport, additive manufacturing, and energy storage solutions. Despite their practical importance, these flows remain poorly understood. As a result, even the most basic properties cannot be predicted reliably. For instance, the best available models over- or underestimate the measured pressure drop in a suspension pipe flow by 30–40% across different flow rates. This makes designing and controlling these flows difficult. The difficulty arises partly because these flows do not fit the conventional ‘laminar’ versus ‘turbulent’ classification; they inhabit a terra incognita. Most theoretical studies so far have focused on confined suspensions in the viscous regime, but this idealized approach is insufficient for practical applications. Finite particle size and velocity introduce complex inertial phenomena, such as particle-induced fluctuations, a gradual transition to turbulence, and shear-induced migration. These effects are at best only qualitatively understood, yet they profoundly alter the flow behavior. Understanding and accurately modelling these flows will enable more energy-efficient transport of industrial slurries, improve our understanding of blood flow, and support the development of sustainable manufacturing processes.

These PhD-positions are part of the ERC Advanced Grant project IDeS where you will join a team investigating densely-laden pipe flows. Two PhD positions are available within the project:

1. PhD 1 will focus on optical techniques to quantify the near-wall behavior using volumetric flow measurement techniques (e.g. Lagrangian particle tracking or tomo-PIV) and model the fluctuations that are introduced by the particles. The interaction of the fluctuations with the transition to turbulence will also be investigated and captured in a physical model.
2. PhD 2 will work on ultrasound imaging velocimetry combined with shadowgraphy to quantify the shear-induced migration of particles, and capture this in a model. The role of volume fraction, particle size, Reynolds number and density ratio will be investigated and captured in a model.
   

While the challenging scientific goals of each project are distinct, we expect a close collaboration to work towards the final goal of being able to predict these flows.

Your work environment
You will be part of the Multiphase Systems group within the Process & Energy Department at TU Delft. The group studies fundamental and applied aspects of multiphase flows, combining advanced experiments and state-of-the-art numerical simulations. Research focuses on dense dispersions, turbulence interacting with free surfaces, and transitions in particle-laden flows, with applications ranging from slurries and food emulsions to 3D printing and transport of floating structures.

Within the group, you will work in a collaborative and international environment, which has access to unique experimental facilities such as MRI, X-ray, and ultrasound imaging, alongside high-performance computing resources. The positions include conducting experimental research, publishing in peer-reviewed journals, presenting at conferences, and mentoring BSc and MSc students. The group values open interaction, knowledge sharing, and teamwork, fostering both individual growth and collective scientific excellence.

Job requirements

We are looking for a self-motivated and creative candidate with:

• An MSc degree in Mechanical Engineering, Chemical Engineering, Applied Physics, or a related field.
• A strong foundation in (multiphase) fluid dynamics.
• Proven experience with experimental work and a drive to explore and improve state-of-the-art techniques.
• Image/data processing skills in Python or Matlab.
• Proficiency in written and spoken English.

Doing a PhD at TU Delft requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis. For more details please check the Graduate Schools Admission Requirements.

TU Delft (Delft University of Technology) 

Delft University of Technology is built on strong foundations. As creators of the world-famous Dutch waterworks and pioneers in biotech, TU Delft is a top international university combining science, engineering and design. It delivers world class results in education, research and innovation to address challenges in the areas of energy, climate, mobility, health and digital society. For generations, our engineers have proven to be entrepreneurial problem-solvers, both in business and in a social context. 

At TU Delft we embrace diversity as one of our core values and we actively engage to be a university where you feel at home and can flourish. We value different perspectives and qualities. We believe this makes our work more innovative, the TU Delft community more vibrant and the world more just. Together, we imagine, invent and create solutions using technology to have a positive impact on a global scale. That is why we invite you to apply. Your application will receive fair consideration. 

Challenge. Change. Impact! 

Faculty Mechanical Engineering 

From chip to ship. From machine to human being. From idea to solution. Driven by a deep-rooted desire to understand our environment and discover its underlying mechanisms, research and education at the ME faculty focusses on fundamental understanding, design, production including application and product improvement, materials, processes and (mechanical) systems. 

ME is a dynamic and innovative faculty with high-tech lab facilities and international reach. It’s a large faculty but also versatile, so we can often make unique connections by combining different disciplines. This is reflected in ME’s outstanding, state-of-the-art education, which trains students to become responsible and socially engaged engineers and scientists. We translate our knowledge and insights into solutions to societal issues, contributing to a sustainable society and to the development of prosperity and well-being. That is what unites us in pioneering research, inspiring education and (inter)national cooperation. 

Click here to go to the website of the Faculty of Mechanical Engineering. Do you want to experience working at our faculty? These videos will introduce you to some of our researchers and their work.

Conditions of employment 

Doctoral candidates will be offered a 4-year period of employment in principle, but in the form of 2 employment contracts. An initial 1,5 year contract with an official go/no go progress assessment within 15 months. Followed by an additional contract for the remaining 2,5 years assuming everything goes well and performance requirements are met. 

Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities, increasing from €3059 per month in the first year to €3881 in the fourth year. As a PhD candidate you will be enrolled in the TU Delft Graduate School. The TU Delft Graduate School provides an inspiring research environment with an excellent team of supervisors, academic staff and a mentor. The Doctoral Education Programme is aimed at developing your transferable, discipline-related and research skills. 

The TU Delft offers a customisable compensation package, discounts on health insurance, and a monthly work costs contribution. Flexible work schedules can be arranged.  

Will you need to relocate to the Netherlands for this job? TU Delft is committed to make your move as smooth as possible! The HR unit, Coming to Delft Service, offers information on their website to help you prepare your relocation. In addition, Coming to Delft Service organises events to help you settle in the Netherlands, and expand your (social) network in Delft. A Dual Career Programme is available, to support your accompanying partner with their job search in the Netherlands.  

Additional information

For more information about this specific position, the research project or the application procedure, please contact Prof. C. Poelma (C.Poelma@tudelft.nl).

Application procedure

Are you interested in this vacancy? Please apply no later than 4 January 2026 via the application button. While you can express a preference for one of the two positions, this is not necessary at this stage.

Please upload the following documents when applying:

• Curriculum vitae
• Motivation letter highlighting your relevant research skills and motivation for doing this PhD project
• Diplomas and transcripts of your BSc. and MSc. studies, including a certified list of grades
• Name and contact details of at least two academic referees (preferably your MSc. thesis supervisor)

You can address your application to Prof. C. Poelma.

Doing a PhD at TU Delft requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis. For more details please check the Graduate Schools Admission Requirements. 

Please note:

• You can apply online. We will not process applications sent by email and/or post. 
• A pre-employment screening can be part of the selection procedure.
• For the final candidates, a knowledge security check will be part of the application procedure. For more information on this check, please consult Chapter 8 of the National Knowledge Security Guidelines. We carry out this check on the basis of legitimate interest.
• Please do not contact us for unsolicited services.