Research & Development @ ÆSIR
At ÆSIR, we have a habit of doing everything ourselves.
That process often results in opportunities to do something new.
Academia has its benefits. By virtue of being students at the Royal Institute of Technology, several of our members have based their Bachelor's and Master's Degree theses on work done right here at the Association. Here you'll find those papers which are available.
We're no strangers to innovation. Theory work is only part of ÆSIR's mission — in the process of building on that research, in developing our systems, we often have to come up with new and unique ways of solving our particular problems. In future iterations of this page, you'll also be able to read about the solutions we've developed in our work.
Academic Papers
Rocket Engine Oxidizer Valve Flow Dynamics
Analysis using Computational Fluid Dynamics
By David Morner and Simon Boström
July 7th, 2025
Abstract | Initiating the combustion process in a hybrid rocket motor using pyrotechnic ignition has a risk of extinguishing the flame and thus the engine. To avoid this, a much lower flow rate can be introduced before opening the main valve supplying oxidiser to the combustion chamber. This thesis investigates the possibility of integrating the pre-flow and fully opened stages in a single valve using an orifice plate design concept and quantifying how the diameter and geometry of such an orifice will affect flow rate and cavitation. [...]
Carbon Fiber Filament Winder
A low-cost alternative to automate consistent winding of composite tubes for rocket technology applications
By Felix Ekman Fjelkestam and Loke Lindberg Nilsson
June 5th, 2026
Abstract | Filament winding is a common manufacturing method for producing composite tubes that are used in areas such as aerospace. However, most machines are far too expensive for the scope of a smaller organization and start-ups such as the student rocketry organization ÆSIR. This thesis aims to find a functional low-cost user-friendly three-axis computer numerical control filament winder capable of consistently winding carbon fiber tubes for rocket applications. [...]
Finding an Empirical Model for a Rocket's Drag Coefficients
A Comparative Analysis with OpenRocket
By Maximillian Seiz de Filippi
July 7th, 2024
Abstract | The accuracy of the calculated drag force in OpenRocket was examined in this investigation for a rocket traveling at subsonic, transonic, and supersonic speeds. The idea was to compare the computed drag coefficients in OpenRocket to the drag coefficients obtained by running multiple computational fluid dynamics (CFD) simulations in Ansys Fluent. Specifically, the freestream Mach number and altitude parameters were varied for a geometric model of the Mjollnir rocket. [...]
Fluid flow features in swirl injectors for ethanol fueled rocket engine
Analysis using computational fluid dynamics
By Emil Vejlens and Dylan de Jourday
June 6th, 2022
Abstract | A swirl injector for a rocket engine being developed by ÆSIR was simulated with different geometric parameters. The swirl injector is used to atomize the ethanol used as fuel and to create a spray that mixes well with the oxidizer within the combustion chamber. Inlet slot angle (90, 75, 60, and 45 degrees), swirl chamber length (15, 20, and 25 mm) and outlet orifice diameter (3, 6, and 9 mm) were examined. [...]