Stabilized Combustion with Single-Port Fuel and Hydrogen Peroxide as Oxidizer

The axial-injection end-burning hybrid rocket has been proposed to address these issues of traditional hybrid rockets. However, backfiring and flame instability occur when liquid oxygen (LOX) is used as the oxidizer. The objective of this study is to verify whether hydrogen peroxide (H₂O₂) can serve as a more manageable substitute for LOX by determining whether stabilized combustion, which represents the fundamental combustion mode of end-burning operation, can be achieved. Single-port fuel grains were fabricated using a high-toughness photocurable resin and tested under various oxidizer flow conditions. Stabilized combustion was confirmed in two cases, with axial regression rates approximately half of those obtained with LOX. All other cases resulted in extinction as LOX cases. While high-velocity extinction agrees with LOX cooling theory, extinction also appeared at low oxidizer flow velocities, likely due to reduced heat release from H₂O₂ decomposition.