Effect of mixing section configurations on combustion efficiency of Mg-CO2 Martian ramjet

Abstract

Experiments were conducted to determine the effects of the mixing section configurations on the Mg-CO2 Martian ramjet combustion efficiency. It was carried out at a mainstream mass flow rate of 110 g/s and a temperature of 810 K. The chamber pressure was measured under different configurations and Oxidizer to Fuel (O/F) ratios. Results showed that the engine achieved self-sustaining combustion and worked stably during experiments. The pre-combustion chamber is needed to increase the combustion efficiency and promote the full combustion of the powder. After the configuration of the pre-combustion chamber, the best combustion efficiency reached 80% when radial powder injection and lateral carbon dioxide intake were used. In addition, the O/F ratio in the pre-combustion chamber decreased from 0.67 to 0.31, resulting in an 8% increase in the combustion efficiency. It was speculated that different mixing section configurations and the variations in an O/F ratio within the pre-combustion chamber impacted the combustion efficiency and in essence, all affected the flow velocity and residence time of the two-phase flow in the combustion chamber.