Combustion evaluation of PU solid fuel based on prepolymer technology additivated with paraffin and Aluminum for hybrid rocket engines

Abstract

The aim of this work is to develop a high regression rate fuel for hybrid rocket motors, this research encompasses binder synthesis and the addition of paraffin and aluminum metallic particles. The project started with the synthesis of polyurethane (binder) based on pre-polymer technology modified with castor oil. These binders were filled with granulated paraffin and micron-sized aluminum particles. Firing tests with 7 configurations were performed. Thrust measurements indicate that the addition of paraffin increased thrust at about 57% and regression rates at about 70%. No relevant improvement in performance was obtained with aluminum addition. Specific impulse decreased when aluminum particles were added to the fuel. The mixture that produced the best ballistic parameters was polyurethane plasticized with castor oil and 30% w/w of paraffin with gaseous oxygen injected with a swirler. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.