Investigation of Bimodal nano/micron Aluminum-Ice (ALICE) Propellants

An experimental investigation was conducted to determine the benefits of bimodal combustion of nano/micron aluminum and ice (ALICE) solid propellant using steadystate strand burner experiments and lab-scale motor static firings. The bimodal distribution ranged from 0% 5-micron aluminum to 50% (by mass) to tailor the burning rate and combustion process of the ALICE propellant, with the remaining aluminum being 80-nm. Burning rates of the bimodal ALICE composition were compared to ALICE propellants containing only 80-nm Al. Equivalence ratios of 0.71 and 1 were investigated using strand burning measurements for the baseline ALICE, while θ=0.71 were used for strand tests containing micron powder addition and motor experiments. The effect of pressure on the linear burning rate was correlated using a Saint Roberts Law power fit. Lab-scale motor tests were to examine the bimodal ALICE propellant performance of promising nano/micron and ice combinations using a center-perforated grain configuration. Pressure, thrust, total impulse and slag accumulation were some of the experimental parameters obtained. Results will be presented that indicate whether micron aluminum particle addition to the baseline propellant increases system efficiency, reduces alumina accumulation, and affects the linear and mass burning rates of the propellant formulations.