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This thesis examines the effects of nanoparticle, metal-oxide additives on the burning rate of composite solid propellants. Recent advancements in chemical synthesis techniques have allowed for the production of improved solid rocket propellant nano-scale additives. These additives show larger burning rate increases in composite propellants compared to previous additive generations. In addition to improving additive effectiveness, novel synthesis methods can improve manufacturability, reduce safety risks, and maximize energy efficiency of nano-scale burning rate enhancers. Several different nano-sized additives, each titania-based, were tested and compared for the same baseline AP/HTPB formulas and AP size distributions. The various methods demonstrate the evolution in our methods from spray-dried powders to pre-mixing the additive in the HTPB binder, and finally to a method of producing the additive directly in the binder as a nano-assembly. Burning rate increases as high as 80% at additive mass loadings of less than 0.5% were seen in non-aluminized, ammonium perchlorate-based propellants over the pressure spectrum of 500 psi (3.5 MPa) to 2250 psi (15.5 MPa). Increases in burning rate up to 73% were seen in similarly formulated aluminized propellants. During the past several years, the research team has refined laboratory-scale techniques for quickly and reliably assessing the mixing and performance of composite propellants with catalytic nanoparticle additives. This thesis also documents some of the details related to repeatability, accuracy, and realism of the methods used in the team’s recent nano-additive research; it also introduces the latest techniques for producing propellants with nano-sized additives and provides new burning rate results for the entire scope of additives and mixing methods. Details on the propellant characterization methods with regard to physical and combustion properties are provided. Snapshots from atmospheric propellant combustion videos taken with a Photron FASTCAM SA3 high-speed camera are included along with existing pressure and light-emission responses.

Idag är de vanligaste använda raketerna flytande-bränsle- och fast-bränsle- raketer. Flytande-bränsle-raketer har fördelen att det kan manövreras men de har en komplex design och problem med förvaring. Fast-bränsle-raketer har en enkel design och kan förvaras men de har en miljöpåverkan och bränslet kan vara svårhanterligt. En tredje typ av raketer, hybridraketer, kan kombinera enkelheten från fasta-bränsle-raketer med manövreringsbarheten från vätske-bränsle-raketer. Trots fördelarna med hybridraketer används de inte på grund av att bränslet har låg regressionshastighet och låg densitet. Organiska additiv har visat sig förbättra dessa egenskaper. 50 organiska additiv granskades med avseende på deras specifika impuls, densitet, kostnad och användarvänlighet. De mest lovande organiska additiven utvärderades sedan experimentellt. Termogravimetrisk analys (TGA), isotermviktförlust, kompatibilitet och differentiell svepkalorimetri (DSC) användes. Resultaten indikerar att hexamin, fluorene, anthracene och 1,4-dicyanobenzene har mest potential att förbättra bränslet i hybridraketer. / Liquid propellant and solid propellant rockets are the most commonly used rockets Liquid propellant rockets have the advantage of being manoeuvrable with a high specific performance while they exhibit problems with storage and a complex design. Solid propellant rockets offer simplicity and are storable while they have a large environmental impact and could be difficult to handle. A third type of rocket, hybrid propellant rocket has the potential to combine the simplicity of solid propellant rocket with the manoeuvrability of liquid propellant rockets. While the hybrid propellant rocket offers advantages over liquid propellant and solid propellant rocket it have problems with its fuel which have a low regression rate and low density. Organic fillers were evaluated since they may increase in the regression rate and the density of the solid fuel. 50 organic fillers were assessed with regards to their specific impulse, density, cost and handling properties. The organic fillers with the most promising properties were then experimentally evaluated. Thermogravimetric analysis (TGA), isothermal weight loss test, compatibility test and differential scanning calorimetry analysis were conducted. The results indicate that hexamine, fluorene, anthracene and 1,4-dicyanobenzene are the most suitable organic fillers of those evaluated..

<p>This work investigated the effects of varying the crystal sizes of ammonium perchlorate (AP) when embedded with a polymeric binder, hydroxyl-terminated polybutadiene (HTPB) on impact-induced temperature behavior.  AP and HTPB are the most used oxidizers and fuel binders in the aerospace solid rocket design industry. In this study, samples of 200 µm and 400µm coarse AP crystals in HTPB were constructed using a conventional hand-mixing method. Using a parametric optimization technique such as the Taguchi method, direct-ink-writing as the additive manufacturing process was used for achieving the required shape fidelity in printing HTPB and by introducing ultraviolet polymers to decrease the curing time.</p> <p>A drop hammer experiment in conjunction with an infrared camera was used to study the impact-induced behavior in the conventionally made AP-HTPB samples. The thermal images obtained from the camera at millisecond resolution are invaluable and provide information about distribution across the sample surface, and the evolution of temperature rise observed in the samples which are complex and not easily understood otherwise and therefore help in improving and attaining desired propellant performance. A two-sample t-Test has been utilized to infer the results and statistical nonsignificance has been observed in the highest temperature rises among 200 µm and 400 µm AP-HTPB sample conditions but a difference in temperature distribution has been observed. A much uniform distribution of temperature over the sample surface on impact is observed in thermal images of 200 µm AP-HTPB sample condition compared to 400 µm AP-HTPB sample condition.</p>