Master Thesis, 30hp: S-ALE Simulation of Projectile Firing in Ansys LS-DYNA

Are you a student eager to apply your theoretical knowledge and fresh perspectives to real-world challenges? At Saab, we believe that innovation thrives on new ideas, and your master thesis project could be the spark that ignites our next technological breakthrough. Your role We recognize the immense value that students bring to our company. Your academic rigor, combined with your enthusiasm for cutting-edge technology, allows you to approach problems with a unique and insightful lens. At Saab, you'll have the opportunity to collaborate with experienced engineers and specialists, gaining invaluable practical experience while making a tangible contribution to our growth and development. Background Simulation of projectile firing involves several strongly coupled physical phenomena, including propellant gas generation, projectile acceleration, interaction between projectile and barrel, counter mass or gas flow, and recoil behavior. Capturing these effects in a single finite element model is challenging and requires careful selection of modelling principles. In Ansys LS-DYNA, Structured Arbitrary Lagrangian-Eulerian, S-ALE, methods offer possibilities to model fluid-structure interaction and highly dynamic gas-driven events. For Saab Dynamics, it is of interest to investigate how S-ALE can be used to represent the complete firing event of a projectile in a recoilless rifle weapon system on a concept level. The purpose of this thesis is not necessarily to validate simulation results against real-life experiments, but rather to investigate suitable modelling strategies and identify practical recommendations for how such simulations can be built and evaluated. Description Of The Master Thesis The aim of this thesis is to set up a concept-level finite element model of a complete projectile firing event in Ansys LS-DYNA, using S-ALE methodology where appropriate. The model should capture the main physical phenomena required to represent the firing event, including:

• burning of propellant,
• propulsion of the projectile,
• propulsion of counter mass and/or propellant gases,
• interaction between projectile and rifling,
• recoil and overall system response.

The work includes studying relevant modelling approaches, setting up representative simulation models, and evaluating which modelling principles are suitable for each part of the event. The focus will be on understanding the modelling methodology, limitations and practical usability rather than achieving fully validated predictive accuracy. The thesis may include:

• Literature review of S-ALE methods and firing-event simulation approaches.
• Investigation of relevant Ansys LS-DYNA capabilities for coupled structural and gas-dynamic simulations.
• Development of a concept-level simulation model for the complete firing event.
• Evaluation of modelling strategies for propellant behavior, projectile motion, counter mass/gas flow, rifling interaction and recoil response.
• Pre-processing and model preparation using Ansys Discovery and Ansys Mechanical.
• Post-processing results in LS-PrePost and scripting in Python or MATLAB.
• Comparison of modelling approaches with respect to physical representativeness, numerical robustness, computational cost, modelling complexity, pre-processing effort and suitability for future concept studies.

The thesis should result in a structured assessment of suitable modelling principles for S-ALE simulation of projectile firing in Ansys LS-DYNA, including recommendations for future development and refinement within Saab Dynamics. The final scope can be adapted depending on the student’s background, interests and available software functionality. This master thesis will be carried out within the Structural Analysis division at Saab Dynamics, Business Unit Ground Combat, with placement in Karlstad/Karlskoga. One site will be your primary location, with occasional travel to the other site when necessary. Your profile This master thesis is suitable for one or two students studying Mechanical Engineering, Engineering Physics, Applied Mechanics, Computational Mechanics, or a similar program. You are approaching the end of your master’s studies and plan to start your thesis work during spring 2027. The thesis corresponds to 30 hp. You have an interest in numerical methods, finite element analysis and structural mechanics. Experience with finite element method and CAD geometry handling is beneficial, but not mandatory. Experience or interest in the following areas is valuable:

• finite element analysis,
• CAD modelling,
• Ansys LS-DYNA or similar simulation tools,
• Python or MATLAB scripting.

You may apply individually or together with another student. If you prefer to perform the thesis together with someone, please state this in your application and include the name of the other student. This position requires that you pass a security vetting based on current regulations concerning security protection. For positions requiring security clearance, additional obligations regarding citizenship may apply. Kindly observe that this is an ongoing recruitment process and that the position may be filled before the closing date of the advertisement. Contact information Robin Heimonen Email: robin.heimonen@saabgroup.com Phone: +46 102173103 Oskar Norman Email: oskar.norman@saabgroup.com Phone: +46 10 – 27 89 124 What you will be a part of Explore a wealth of possibilities. Take on challenges, create smart inventions, and grow beyond. This is a place for curious minds, brave pioneers, and everyone in between. Together, we achieve the extraordinary, each bringing our unique perspectives. Your part matters. Saab is a leading defense and security company with an enduring purpose, to help nations keep their people and society safe. Empowered by its 28,000 talented people, Saab constantly pushes the boundaries of technology to create a safer and more sustainable world. Saab designs, manufactures and maintains advanced systems in aeronautics, weapons, command and control, sensors and underwater systems. Saab is headquartered in Sweden. It has major operations all over the world and is part of the domestic defense capability of several nations. Read more about us here.