PhD Wind Energy Vortex Generators in 3D Unsteady Flows (VoGUe) | Petten

As a PhD in the Wind Energy research group, you will work with topic experts to further explore the versatile field of wind energy research and help create a sustainable future using renewable energy sources!



Education type

university (wo)



Hours a week

Fulltime – 40


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What will you be doing?

You will be employed at TNO as a PhD researcher and enrolled as a PhD student at the Delft University of Technology. As a PhD student you are supervised by research staff at TNO and academic staff at TU Delft. You will have the opportunity to collaborate on the technologically challenging projects of the Wind Energy research group at TNO and be part of the Department of Aerodynamics, Wind Energy and Propulsion of the Faculty of Aerospace Engineering of the TU Delft. You will also be part of the Graduate School of the TU Delft. 

The quest for robust and higher power output at reduced costs per offshore wind turbine drives the design towards increasingly larger rotor diameters that have positive influence on the usage of the electrical grid (by larger capacity factor) and wind farm power production. To counter the increased mechanical loading in extreme off-design conditions these increasingly larger rotors have relatively small solidity. The much slender rotors therefore have to be equipped with thicker rotor blades. The drawback of thicker blade sections is their use is accompanied with large uncertainties in performance. This is motivating the application of vortex generators (VG) and thick trailing edges. 

VGs are commonly used on wind turbine blades to avoid early separation of flow which helps not only to increase the lift but also delays the stall leading to increased blade robustness. Delaying the stall angle of wind turbine blades will allow for operation over larger range of angle of attacks and thus increase power production from wind turbines. Although effects of VGs are studied by various researchers a model depicting the effects of these devices in an aerodynamic design tool is important to design state of the art airfoil sections/wind turbine blades. Furthermore, this project aims to investigate and model the effects of VGs in unsteady flow conditions, which is a challenging new research topic.

In this project we will approximate the effects of the VGs on the 2-D unsteady boundary layers so that it can be modelled as additional mixing in the fast and accurate aerodynamic design tools based on integral boundary layer equations (e.g. RFoil). The presence of a new shear layer will lead to additional viscous dissipation and affect the wall shear stress. To model these effects, new terms are introduced into the integral boundary layer equations to account for the extra mass and momentum flux and turbulence production. Both TNO and TUDelft have developed preliminary models to account for these effects and these models will be integrated. 

About TNO
TNO is an independent research organisation that functions as a bridge between the worlds of academia and industry, and the public sector. TNO has around 3,500 employees working within nine domains for a wide range of clients, such as government agencies, the SME sector, civil society organisations, larger companies and service providers. We aim to translate research findings into straightforward applications and innovations to solve the challenges the world will encounter the day after tomorrow. We take the time to think calmly and thoroughly about issues and, once a project has been completed, we continue our search for tools, models and recommendations that will benefit our clients and society as a whole in the future.
Read more about TNO as an employer 

What do we require of you?

You have a good set of brains, a passion for renewable energy in general and wind energy in particular, and great social skills. After all, you will always be working with others, as part of project teams or larger consortiums to solve societal issues. You don’t have to know everything about the entire field (although we wouldn’t mind it if you did). The most important thing is that you have a broad interest in applied scientific research and a passion for wind energy and similar topics. You’re also not afraid to get out of your comfort zone and are eager to develop further.

Other qualifications we’re looking for:
  • An MSc degree in Aerospace Engineering from a well-established university, or an MSc degree in related engineering disciplines such as applied physics, applied mathematics, or mechanical engineering with a proven experience (courses, projects, work experience) in the field of computational fluid mechanics. 
  • A combination of good mathematical/analytical skills and a strong interest in high-fidelity numerical simulations is required. 
  • Experience with CFD methods (such as SU2, OpenFOAM) is preferred. 
  • Proven experience with such simulations and related data processing is advantageous for this position.
  • Since an important part of research work is dissemination and collaboration, fluent communication skills, both written and orally, in English are of utmost importance. 
  • Female scientists are particularly encouraged to apply.
The research will start with a literature survey on the vortex generators (VGs) and modelling concepts for the higher and lower fidelity methods including the mathematical model developed by TNO. Previous experimental study and numerical (CFD) simulations will give an insight about the VGs and the model.

As a next main task CFD simulations (with an open source tool, e.g. SU2, OpenFOAM) will be performed on airfoil sections with and without VGs to construct the model data and the extend the original model. The first milestone will be implementing the steady VG model in RFOIL. This study will be supported by experimental data provided by partners of the project. The experiments will also contain information about unsteady flow conditions. The effect of these unsteady flow conditions in combination of VGs will be evaluated.  A new set of innovative airfoil sections will be designed in various thicknesses that are optimized for VGs and thick trailing edges.

As the final main task of the research the PhD student will investigate the existing BAY VG model(s) as implemented in the open source CFD tools (e.g. OpenFOAM) and improve this model for the unsteady flow conditions. In order to see the effects of the VGs on the 3D flow, numerical simulations will be performed for relevant Reynolds numbers both with the BAY model and body fitted mesh. The unsteady velocity field will be analysed to get a better insight of the flow field. A new innovative blade will be designed including the effects of vortex generators. In the blade design the airfoil sections designed previously will be used.


View Marcelien Bos-de Koning's vlog about wind energy at the North Sea.

What can you expect of your work situation?

Within TNO, you’ll be part of the Wind Energy research group, which is part of the Unit Energy Transition. You’ll work with leading researchers who’ve been active in the field for years, as well as with co-workers with a fresh, enterprising take on things. It’s a highly diverse and social bunch, from many different countries and backgrounds, who will make you feel right at home. Our Wind Energy team is renowned worldwide for its research into wind energy, and you may have heard us referred to as ECN. Our testing facilities and the research objects you'll come into contact with are truly unique, such as the 260 metre high Haliade-X wind turbine in Rotterdam, or the Lelystad-based smart energy field lab. You’ll spend most of your time at our research facility along the Dutch coast in Petten, near Alkmaar. We’re also currently in the process of opening a new facility in Delft, which thus may end up being your home in near future. Furthermore due to the cooperation, the main office of the PhD student will be in TNO, Petten. Student is expected to visit TU Delft regularly.
Read more about the Wind Energy research group
Look at the TNO Wind Energy video

Research facilities and information about TU Delft Faculty of Aerospace Engineering 
The faculty of Aerospace Engineering at Delft University of Technology is one of the world's largest faculties devoted entirely to aerospace engineering. In the Netherlands, it is the only research and education institute directly related to the aerospace engineering sector. It covers the whole spectrum of aerospace engineering subjects. In aeronautics, the faculty covers subjects ranging from aerodynamics and flight propulsion to structures and materials and from control and simulation to air transport and operations. In astronautics, topics include astrodynamics, space missions and space systems engineering. The faculty has around 2,500 BSc and MSc students, 225 PhD candidates and 30 professors supported by scientific and technical staff.

The position will embedded in the Department of Aerodynamics, Wind Energy and Flight Performance and Propulsion (AWEP), one of four departments composing Aerospace Engineering. Fundamental aerodynamic research is performed in the Aerodynamics section. The aerodynamics of wind turbines and wind farms is a key research area in the Wind Energy section. The department operates comprehensive laboratories, equipped with modern wind tunnels and state-of-the-art measurement systems.

The Wind Energy Section facilitates the development of wind energy technology and the expansion of the use of wind power through research and education. In its research activities there is a focus on large multi megawatt offshore wind turbines and offshore wind farms, though urban and airborne wind power is also addressed. Both technology development aspects as well as fundamental aspects are present in the research program. 
Information about the TUD Faculty of Aerospace Engineering

What can TNO offer you?

We offer you work that is both challenging and diverse, as well as plenty of opportunities for personal development; you’ll be largely in charge of your own career. In addition to a gross monthly salary of € 2880,00, holiday pay and a thirteenth month salary, you’ll get every opportunity to develop further and explore your professional field in-depth and become a scientific specialist or continue on into alternative career paths towards for example the role of project leader. TNO also allows you to pick and choose from a ‘menu’ of employee benefits in line with your personal situation. Here are some more benefits to consider:
•    The prospect of a fixed contract if all goes well after the 4 years of PhD ship.
•    28 days of annual leave and 5 days of reduced working hours (based on a full-time contract).
•    Flexible working hours and the option of working from home.
•    The option of participating in training courses or additional schooling, and visiting conferences.
•    Access to our Talent Development Programme and personal coaching.
•    Networking opportunities.
•    A travel allowance or a bicycle on loan.
•    Fun outings and activities, such as monthly drinks events, with your team and colleagues at your workplace, as well as other TNO facilities. These events will quickly help you get to know lots of people.
•    An incredibly professional, inspiring work environment, with colleagues who are the top experts in their respective fields.
•    A sound retirement plan.
•    Comprehensive relocation package for international applicants.
•    The PhD candidates will be working partly at TNO and at the Delft University of Technology.

Read all about the many employee benefits to choose from.

Application process

Your PhD research will be guided by TNO and TU Delft. That means that the successful PhD candidate will be an employee of the Wind Energy Group at TNO and work under the guidance of Dr. Huseyin Ozdemir and supervision of Carlos Ferreira at the TU Delft University.

For more information about this position, please contact:
Supervisor at TNO - Dr. Huseyin Ozdemir, phone: +31 (0)625714368, email: 
Mentor at the TU Delft University  - Carlos Ferreira, phone: +31 (0)15-2782073, e-mail:

We are accepting applications until March 14th 2021. The application process will consist of two selection interviews, followed by a third and final interview to discuss your employee benefits. An online assessment, reference check and final presentation can be part of the selection procedure.

Due to the measures that have been implemented to combat Covid-19, the application process and on-boarding for new employees have been modified. More information regarding these matters will be included in the invite for a first interview.

Has this vacancy sparked your interest?

We look forward to receiving your application! For more information about the position or the application process, please feel free to contact us.

Recruiter: Paul Verschoor
Mobile phone: +31 (0)6-29236794

Hiring manager: Marc Langelaar
Phone number: +31 (0)88-86 63060

Note that applications via email and third party applications are not taken into consideration.


Apply now


Dr. Marc Langelaar

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