Boundary layer combustion visualization in hybrid rocket engines

Kurzfassung

The present research focuses on the development of an optical testing routine and a combined improved analysis methodology. The final aim is the characterization of the combustion process in a detailed way, thus getting insights into the complex phenomena taking place within a hybrid engine. A pre-existing optical combustion chamber has been improved by adding a newly designed flow conditioning system, whose scope is to settle down the oxidizer flow and reduce its vorticity and inhomogeneities before entering the main chamber. The set-up has been validated through a test campaign, carried out at the German Aerospace Center (DLR) in Lampoldshausen. Moreover, a code for the high-speed video analysis, based on the combination of K-means clustering and image segmentation, has been developed. At the end of the algorithm, the flame and fuel profiles are reconstructed for each frame, thus obtaining the flame thickness and the slab regression rate evolutions during combustion.