Effects of helium injection scheme on the thrust performance of solid-gas hybrid rocket motor

Release time:2025-12-22  Hits:

• Impact Factor:5.8
• DOI number:10.1016/j.ast.2025.111096
• Journal:AEROSPACE SCIENCE AND TECHNOLOGY
• Place of Publication:中国
• Key Words:Solid-gas hybrid rocket motorSpecific impulse gainActive thermal protectionGas dynamics
• Abstract:To improve the thrust performance of solid rocket motors and provide active thermal protection for nozzles, this paper numerically investigates two novel configurations for solid-gas hybrid rocket motors, namely helium injection in nozzle convergent section, and combined head-end/nozzle convergent section helium injection. Results demonstrate 5.44 % maximum specific impulse gain and 100 %- 278 % thrust regulation range for the combined injection scheme. Moreover, the helium injected from the nozzle convergent section flows along the nozzle wall, reducing the temperature of the nozzle wall by more than 60 %. For the helium injection at nozzle convergent section, the transverse jets improve the mixing and radial thermal convection, narrowing the velocity disparity of mixed gases with varying helium mass fractions. One-dimensional gas dynamics analysis reveals that a low helium injection ratio ensures the velocity gain from reduced gas molecular weight outweighs the loss induced by total temperature reduction, thus enhancing specific impulse. For the combined helium injection scheme, helium gas and combustion gas form a "sandwich" structure, further enhancing the expansion and work capacity of the mixed gas. Consequently, this configuration delivers superior thrust performance compared to a single helium injection scheme while also providing active thermal protection for the nozzle.
• Note:中科院1区，Top期刊
• Indexed by:Journal paper
• Document Code:111096
• Discipline:Engineering
• Document Type:J
• Volume:168
• Issue:E
• ISSN No.:1270-9638
• Translation or Not:no
• Date of Publication:2025
• Included Journals:SCI
• Links to published journals:https://doi.org/10.1016/j.ast.2025.111096