• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.456-461
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• 2017

In this study, the rheological properties of nitromethane gel propellants on nano/micron sized gelling agent are investigated. Silicon dioxide is used as the gellant with 5 wt%, 6.5 wt% and 8 wt% concentration, respectively, where the measurements are conducted under steady-state shear flow conditions using a rotational rheometer. The nitromethane/silicon dioxide gel showed non-Newtonian flow behavior for the entire experimental shear rate ranges. The gel fuels with nano-sized gellant had a slightly higher viscosity than the gel fuels with micron-sized one for low shear rate range. Additionally, it was found that Herschel-Bulkley model can hardly describe the rheological behavior of nitromethane gel propellant, but the NM model(by Teipel and Forter-Barth) is better suited to explain the rheological behavior of nitromethane gel propellant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.329-334
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• 2005

The rocket grade hydrogen peroxide has been widely used as a monopropellant in propulsion systems. Conventional decomposition of hydrogen peroxide, however, requires preheating before feeding into the reactor. In the present paper, we described an experimental study of a catalytic reactor bed that employs multiple catalysts to enhance the low temperature response in the vicinity of the reactor inlet. $K_2MnO_4$ is experimentally chose as the inlet catalyst from the candidates of silver, platinum, $La_{0.8}Sr_{0.2}CoO_3(LSC),\;and\;K_2MnO_4$. We developed new synthesis and coating method using modified alumina sol-gel method to strengthen the adhesion of $K_2MnO_4$ catalyst. from the vaporizer experiment with hydrogen peroxide at room temperature, satisfactory vaporizing performance was measured.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.87-92
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• 2006

The rocket grade hydrogen peroxide has been widely used as a monopropellant in propulsion systems. In the present paper, we described an experimental study of a catalytic reactor that employs two stage catalyst beds to enhance the low temperature performance of the reactor inlet. $K_2MnO_4$ was chosen as the catalyst for the initial stage of the reactor bed for its superior behavior in the low temperature regime. Alumina sol-gel method was successfully applied for coating $K_2MnO_4$ on a reactor bed of cordierite monolith. LSC was used for the catalyst of the second stage of the reactor. The reactor with combined catalyst beds was built and tested to exhibit superior performance in low temperature regime and high decomposition efficiency.