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Results for “AMMONIUM PERCHLORATE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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Shear and combustion characterization of printable ammonium perchlorate composite propellant formulations

Seven formulations of ammonium perchlorate composite propellant (APCP) are developed and their properties relevant for successful additive manufacture are characterized. Extrusion in a custom-built 3D printing system and spindle viscometry are used to collect viscosity measurements of curing primary and non-curing secondary versions of the formulations. The formulations that behave similarly to a Bingham plastic, with apparent viscosities between 4 and 8 thousand Pa*s at 30 minutes post-mix, are determined to be most suitable for printing applications. Measurements of one material show a yield stress of 1 kPa. Ambient pressure burn rates of 2.0–2.9 mm/s were measured for the compositions tested. All measured burn rates were comparable to the lower end of typical burn rates for APCP. In conclusion, the results of the characterization demonstrate a propellant suitable for use in a 3D printing system.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Acid-base synthesis of aluminum iodate hexahydrate powder as a promising propellant oxidizer

In this study, an acid-base precipitation reaction is detailed to synthesize pure crystals of the oxidizer rich compound [Al(H 2 O) 6 ](IO 3 ) 3 (HIO 3 ) 2 and described here for the first time. The molecule is called aluminum iodate hexahydrate (AIH) and characterized for its energetic potential as an oxidizer in propellant applications. The synthesis method produced bipyramidal hexagonal crystals that are characterized physically and chemically by microscopy, pycnometry, and X-ray crystallography. Further energetic characterization is performed by bomb calorimetry, and impact, friction, and electrostatic discharge ignition sensitivity. This study introduces the potential of AIH as an alternative solid propellant by comparison to the properties of ammonium perchlorate (AP) and ammonium nitrate (AN).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Swelling and permeability effects during propellant cookoff

Large rocket motors may violently explode when exposed to accidental fires. Even hot metal fragments from a nearby accident may penetrate the propellant and ultimately cause thermal ignition. A mechanistic understanding of heated propellants leading to thermal runaway is a major unsolved problem. Here we show that thermal ignition in propellants can be predicted using a universal cookoff model coupled to a micromechanics pressurization model. Our model predicts the time to thermal ignition in cookoff experiments with variable headspace volumes. Furthermore, we found that experiments with headspace volumes are more prone to deformation which distorts pores and causes increased permeability when the propellant expands into this headspace. Delayed ignition with larger headspace volume correlates with lower headspace pressures during decomposition. We found that our predictions matched experimental measurements best when the initial propellant was impermeable to gas flow rather than being permeable. Similar behavior is expected with other energetic materials with rubbery binders. Our model is validated using data from a separate laboratory. We also present an uncertainty analysis using Latin Hypercube Sampling (LHS) of thermal ignition caused by a steel fragment embedded in the propellant.

33 ADVANCED PROPULSION SYSTEMS↗