EFFECTS OF METHANOL AND FUMED SILICA ON LINEAR BURNING RATES OF AQUEOUS HYDROXYLAMMONIUM NITRATE

摘要

The linear burning rates of aqueous hydroxylammonium nitrate (HAN) solutions containing methanol and nanoscale fumed silica were observed in a strand burner at pressures between 3 and 22 MPa. Measurements were completed using a previously verified pressure-based method that does not require direct observation of the propellant burning surface. The baseline solution contained 82.4% HAN by weight, while methanol and fumed silica powder were separately added to this baseline mixture at an additional 14.9% and 1% by weight, respectively. Baseline burning rates and light emission phenomena compared favorably with similar solutions studied by other research groups using more complex optical techniques. The addition of 14.9% methanol resulted in burning rates that could be over 12.5 times faster than the baseline rates at lower chamber pressures, while the presence of 1% fumed silica nanoparticles yielded burning rates that were over 7.3 times faster at lower pressures. All tested mixtures exhibited drastic changes in burning behavior between certain pressure regimes, and the presence of methanol caused a much greater deviation from the overall shape of the baseline burning rate curve. The current study expands the range of chamber pressures tested for aqueous HAN and HAN/methanol solutions while exploring the use of metal oxide additives to tailor combustion behavior without radically altering the burning curve shape, with the future goal of creating and testing novel nanofluids based on HAN and methanol.