Chemical rocket propulsion systems can be divided into solid, liquid, and hybrid propellant systems. Despite the numerous benefits that hybrid rocket systems enjoy over both solid and liquid propellant systems, their widespread implementation has not yet been achieved. This is due to the low regression rates of classical non-liquefying hybrid fuels, as well as the poor mechanical properties generally possessed by higher performance liquefying hybrid fuels.
Previous works into improving the mechanical properties of liquefying fuels, such as paraffin, generally were limited to the blending of the paraffin with polyethylene, which does provide some improvement, but also slightly decreases the regression rate of the paraffin fuel. This research presents an investigation on the effect of the addition of an internal skeleton composed of ABS on the performance of a Paraffin/GOX hybrid propellant system.
The most important findings of this research were the significantly increased regression rate observed for the grains that possessed ABS structures when compared to the regression rate for grains composed solely of Paraffin, this added regression rate was also accompanied by better mixing between the fuel and oxidizer, as well as a higher combustion efficiency. For the oxidizer fluxes studied the regression rates of the ABS grain was approximately .2 mm/s, of the pure paraffin grain about 1 mm/s whereas for the ABS-paraffin structure the regression rate reached 1.4-1.6 mm/s, which seems to be a great improvement.
