A review of the performance and structural considerations of paraffin wax hybrid rocket fuels with additives
| Autor: | Jean Pitot, Michael J. Brooks, Kirsty L. Veale, Sarp Adali |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Propellant 020301 aerospace & aeronautics Wax Materials science Aerospace Engineering Rocket propellant 02 engineering and technology Polymer 01 natural sciences 010305 fluids & plasmas Viscosity Low-density polyethylene Brittleness 0203 mechanical engineering chemistry Paraffin wax visual_art 0103 physical sciences visual_art.visual_art_medium Forensic engineering Composite material |
| Zdroj: | Acta Astronautica. 141:196-208 |
| ISSN: | 0094-5765 |
| DOI: | 10.1016/j.actaastro.2017.10.012 |
| Popis: | Paraffin wax as a hybrid rocket fuel has not been comprehensively characterised, especially regarding the structural feasibility of the material in launch applications. Preliminary structural testing has shown paraffin wax to be a brittle, low strength material, and at risk of failure under launch loading conditions. Structural enhancing additives have been identified, but their effect on motor performance has not always been considered, nor has any standard method of testing been identified between research institutes. A review of existing regression rate measurement techniques on paraffin wax based fuels and the results obtained with various additives are collated and discussed in this paper. The review includes 2D slab motors that enable visualisation of liquefying fuel droplet entrainment and the effect of an increased viscosity on the droplet entrainment mechanism, which can occur with the addition of structural enhancing polymers. An increased viscosity has been shown to reduce the regression rate of liquefying fuels. Viscosity increasing additives that have been tested include EVA and LDPE. Both these additives increase the structural properties of paraffin wax, where the elongation and UTS are improved. Other additives, such as metal hydrides, aluminium and boron generally offer improvements on the regression rate. However, very little consideration has been given to the structural effects these additives have on the wax grain. A 40% aluminised grain, for example, offers a slight increase in the UTS but reduces the elongation of paraffin wax. Geometrically accurate lab-scale motors have also been used to determine the regression rate properties of various additives in paraffin wax. A concise review of all available regression rate testing techniques and results on paraffin wax based hybrid propellants, as well as existing structural testing data, is presented in this paper. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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