The objective of this thesis project was to investigate the effects of subcooling high-purity grade propaneto cryogenic temperatures using nitrogen bubbling. The primary objective was to investigate the effects on impurities and the diffusion of nitrogen into the propane. The study also aimed to gain practical and theoretical experience in experimental testing. Therefore, the thesis work involved the design and construction of a test rig called Nordri, the development of a complex sampling method, and the analysis of sample quality and composition. Unexpected events during the test were also addressed.

This work provides valuable data for future research in the field, and the developed the test rig Nordri does also enable future experimental studies and research to be conduced within the new niche field of utilizing high-purity grade propane as rocket fuel. Overall, this thesis project contributed to the field of subcooling propane as a rocket fuel and provided valuable theoretical and practical experience in experimental design, data analysis and interpretation, and instrumentation. The project was carried out in collaboration with Isar Aerospace Sweden AB, and the research findings are intended to benefit the company’s operations.