Catalytic Decomposition of N2O4 to N2 and O2 to Improve Isp

摘要

Complete combustion in liquid bipropellant systems needs excess amounts of oxidizer. The excess amounts of oxidizer will reduce the specific impulse (1sp) due to its high molecular weight. To enhance 1sp, it is necessary to convert the outlet excess oxidizer from the combustion chamber to low molecular weight products without a decreasing in combustion chamber temperature (Tc). In this paper, a suitable method was proposed in converting N2O4 (a conventional oxidizer for hydrazine fuels) to N2 and 02. According to the method, decomposition of N2O4 to N2 and O2 occurred by deposition of transition metal catalysts on the combustion chamber wall. Due to expense of the catalysts, low amounts of catalysts were used by nanosizing them. The results showed a conversion at least 80% of N2O4 (to N2 and O2) and a reduction of 17% of outlet molecular weight products from combustion chamber. A rough theoretical calculation showed at least 10% enhancement in 1sp. Also a new technique is given to deposit the nanocatalyst on the combustion chamber wall.