Graduation internship | Modelling fragment trajectories following explosions

When working with explosives, it is essential to reliably determine safe separation distances. This graduation project directly contributes to improving the safety of people and equipment by enhancing models that predict how (metallic) fragments travel through the air following an explosion. You will work on innovative analysis methods that are applied in safety assessments for both civilian and military applications.

What will be your role?

You will investigate how the flight behaviour of arbitrarily shaped, oriented, and potentially rotating fragments following an explosion can be modelled more accurately. The goal is to robustly describe the aerodynamic behaviour of these fragments using one or more analytical models, thereby improving the reliability of fragment trajectory simulations.

You will analyse how aerodynamic effects are currently incorporated into models and which assumptions are made in the process. Current state-of-the-art models are often based on point-mass approaches that use experimentally determined drag coefficient data as input. This approach is effective and widely applicable, but there is also room for further refinement. You will explore how existing models can be extended or improved to better reflect the actual behaviour of fragments.

Depending on your interests and background, your work may combine literature research, data analysis, numerical simulations (CFD), engineering tools, and potentially experimental research, such as ballistic testing (at TNO) or wind tunnel measurements (at the university).

What we expect from you

You are analytical, curious, and enjoy getting to grips with complex physical problems. You are able to work independently, while also actively seeking collaboration with colleagues.

What else you bring:

• You are pursuing a Master’s degree in Aerospace Engineering, Mechanical Engineering, Applied Physics, or a related field
• An interest in aerodynamics, modelling, and/or ballistics
• An affinity for numerical simulations (e.g. CFD) and/or experimental research
• Fluent in English, both written and spoken

What you can expect from your working environment:

You will be part of the Platform Protection & Advanced Materials (PPAM) department. The department is part of TNO’s Defense, Safety & Security (DSS) unit and consists of approximately 45 colleagues working on the development and testing of munition effects, protection concepts for vehicles, and advanced (protective) materials against ballistic threats and explosions. Much of this work is carried out in the military domain, with part of the work focused on civilian applications. With our support, new protection technologies are developed that are ultimately deployed by units of the Dutch Armed Forces, as well as, in many cases, foreign armed forces and police forces. Within the department, both theoretical and experimental research is conducted.

What you'll get in return

An internship at TNO means working in an environment where substance and impact are central. You will become part of a knowledge organisation where research and practice come together, and where experts collaborate on solutions to current societal and technological challenges.

Your internship is a period in which you can discover what suits you, where your strengths lie and what you would like to learn next. You are part of a professional working environment, gain insight into how things work in practice, and have the opportunity to build experience that goes beyond this internship alone. For many students, an internship is therefore also a first step in discovering whether TNO could be a potential next step after graduation.

In addition, we offer you:

• A professional and innovative internship environment in which you actively contribute to societal and technological challenges, working alongside leading experts in your field.
• Personal and dedicated supervision, with focus on your learning objectives, development and study assignment.
• Room to develop: you gain relevant work experience, develop both your subject‑specific and professional skills, and build a valuable network.
• Use of a laptop and the facilities you need to perform your work effectively.
• A monthly internship allowance of € 615 for a full-time internship, for MSc, BSc and vocational education (MBO) students.
• Up to eight hours of leave per internship month for a full-time internship, allowing you to balance your internship with your studies and personal life.
• A contribution towards travel expenses if you are not entitled to a student travel card.
• A free membership to Jong TNO: the network for young colleagues, where you can meet other TNO colleagues and participate in sports activities, professional and personal development activities, and social events such as the annual ski trip.

Our people are at the heart of TNO. Their curiosity, expertise and entrepreneurial mindset make it possible to deliver high-impact research and innovations that contribute to society’s sustainable wellbeing and prosperity. That is why we invest in an inspiring and inclusive working environmentwhere colleagues can excel, have autonomy and continue to grow.

Your talent and ambition have every opportunity to flourish at TNO. You work with experts (both within and beyond TNO), have access to advanced technology and the freedom to explore, experiment and innovate. Our strength lies in independence, reliability and collaboration. We find each other in wonder and ingenuity. We are driven to push boundaries. By working with businesses and government, and by connecting different perspectives, we strengthen our innovative capability and create responsible, meaningful results.

At TNO, we believe this is our time to help society, government and business move forward faster. Together with driven colleagues, you turn knowledge into concrete innovations or ventures that truly make a difference by combining the power of science and entrepreneurship. And in doing so, you make your mark on our time.

The selection process

You can apply for this internship position until the 25th of September, 2026. After submitting your application, you will receive a confirmation by email.

TNO will arrange an appropriate internship agreement. If you have any questions about the content of the internship or the application procedure, you can contact the person listed below.

If you start an internship with us, we will also ask you to provide a Certificate of Conduct (VOG).

For this internship vacancy it is required that the AIVD issues a security clearance (VGB) following a security screening. In any case, please note that this process has an average duration of approximately 8 weeks. If you have been abroad for more than 6 consecutive months, or if you do not have the Dutch nationality, this process may take longer.

Important to know before applying:

• Before the start of the internship, an internship agreement must be signed. For students enrolled at a Dutch university or university of applied sciences, TNO uses the UNL-template, supplemented with several TNO‑specific agreements. For students from foreign educational institutions and MBO (secondary vocational education) programmes, the TNO internship agreement applies. TNO does not sign any other internship agreements.
• Before the start of the internship, the educational institution will need to confirm in writing that:
  1. you are enrolled at the educational institution for the duration of the internship, and;
  2. the internship forms part of your study programme.

The confirmation of educational institution takes place by signing the UNL template or forms prepared by TNO.

• Interns at TNO must have a registered residential address in the Netherlands at the start of the internship. Carrying out internship activities from abroad is not possible.
• Are you an international student? Please note that you must have a BSN (Dutch citizen service number) before the start of your internship. Applying for a BSN can take several weeks, so make sure to start this process well in advance.