Rheological, optical, and ballistic investigations of paraffin-based fuels for hybrid rocket propulsion using a two-dimensional slab-burner

¹ Deutsches Zentrum für Luft- und Raumfahrt (DLR) Institute of Space Propulsion Hardthausen D-74239, Germany
² Politecnico di Milano, Aerospace Engineering Department Space Propulsion Laboratory (SPLab) Milan I-20156, Italy

Abstract

This paper describes combined rheological, ballistic, and optical analyses performed on paraffin-based mixtures that can be used as high regression rate hybrid rocket fuels. Experimental activities have been done at the DLR Institute of Space Propulsion in Lampoldshausen and at SPLab of Politecnico di Milano [1]. Herein, the experiments that were performed at the DLR are described in detail. Viscosity, surface tension, and regression rate of the fuels have been determined. Furthermore, the combustion was evaluated by optical measurements. Data collected so far indicate an increasing regression rate for decreasing viscosity of the liquid paraffin which is in accordance with the current theories. Droplet entrainment, which is related to high regression rates, is only visible for the low-viscosity paraffin-based fuels.