Production technique effects on the mechanical and ballistic properties of paraffin-based fuels

This thesis focuses on the impact of the manufacturing procedure on the mechanical and ballistic properties of paraffin-based fuels. At lab-scale level paraffin grains for HREs testing are typically prepared by melt-casting. This approach could be not suitable at industrial level, due to the paraffin shrinkage after casting. Thus, this work aims at assessing the possible benefits of paraffin manufacturing without melting. This objective is pursued by joined mechanical and ballistic analyses performed on solid fuel grains suitable for testing in a lab-scale motor. Melt casted samples ar taken as reference for the relative grading of formulations based on different techniques, and exploiting new approaches for the dispersion of additives required for efficient paraffin combustion.

Questo lavoro di tesi si concentra sull'impatto di diverse procedure di manifattura sulle proprietà meccaniche e balistiche di propellenti a base di paraffina. A scala di laboratorio, i grani di propellente vengono tipicamente prodotti tramite processo di fusione. Questo approccio non può però essere pensato su scala industriale, a causa dei problemi di ritiro volumetrico durante la fase di solidificazione (shrinkage). Pertanto, questo lavoro mira a valutare i possibili benefici della produzione di paraffina senza passare per la fusione.