Abstract One of the issues of using a normal graphite nozzle for the hybrid rocket propulsion is the serious throat erosion due to combustion with a higher O/F ratio. This may undermine the throttling capability of the hybrid rocket engine. In this study, we would like to address how the propulsion performance changes under the conditions of different nozzle throat diameters and O/F ratios. We designed and tested a 40-kgf class single-port hybrid rocket motor with the swirling injection of oxidizer, which utilizes the 90 wt% hydrogen peroxide and polypropylene (PP) as oxidizer and fuel, respectively. Three different diameters of graphite nozzle throat (10, 11, and 12 mm) were used to approximate various conditions of nozzle erosion, while the mass flow rates of the injected oxidizer were kept the same. The hot-fire test results indicated that the thrust was nearly the same even the nozzle throat diameters and O/F ratios were different. Especially, the discrepancies among the measured thrusts and oxidizer ISP under various test conditions were found to be less than 1%, which is highly beneficial for the purpose of the thrust control using mass flow rate control of the oxidizer for a hybrid rocket engine with swirling injection of high-concentration hydrogen peroxide.
Highlights A simple method is proposed for designing the plumbing system of a H2O2-PP hybrid rocket engine. ISP of a H2O2-PP hybrid engine is not affected much by nozzle throat erosion in some O/F ratio shift. Same ISP with O/F ratio shift in various nozzle throat diameters is explained through experiments. Hybrid-engine thrust can be controlled by controlling the flow rate even with nozzle throat erosion.
Experimental investigation of the effect of nozzle throat diameter on the performance of a hybrid rocket motor with swirling injection of high-concentration hydrogen peroxide
Acta Astronautica ; 164 ; 334-344
2019-07-31
11 pages
Article (Journal)
Electronic Resource
English