| Abstract: | Effect of addition of carbon in the form of graphite and carbolac on the combustion characteristics of Magnesium-Sodium nitrate propellant has been studied. Results indicated that the burning rate of the propellant increased significantly by the addition of graphite upto 2%. Thermal decomposition studies revealed that the graphite particles in addition to its absorption of thermal energy being an inert material react with the decomposed products of the sodium nitrate just above the burning surface of the propellant for the exothermic heat release. This heat release which is high at low concentration of graphite is seen causing high burning rate. Any further increase in graphite concentration beyound 2% reduces the burning rate as the thermal energy absorption exceeds the heat release at the burning surface. When carbon in the form of carbolac was used in the composition reactive species diffuse out prior to the sample ignition without participating in the combustion thus reduces the burning rate. The heat of reaction data supported the suggested mechanism. |
