Comprehensive Scientific Study on Propulsion Systems of Liquid Hydrogen and Hybrid Fuel Rocket Engines


Mulcar H., Sağıroğlu S., Gürbüz H.

11th Azerbaijan Congress on Life, Engineering, Mathematical, And Applied Sciences, Baku, Azerbaycan, 21 - 22 Haziran 2025, cilt.1, ss.164-171, (Tam Metin Bildiri)

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Cilt numarası: 1
  • Basıldığı Şehir: Baku
  • Basıldığı Ülke: Azerbaycan
  • Sayfa Sayıları: ss.164-171
  • Süleyman Demirel Üniversitesi Adresli: Evet

Özet

This study provides a comprehensive scientific review of liquid hydrogen (LH2) and hybrid fuel

rocket engines in terms of propulsion systems. Technical parameters such as performance, safety,

environmental impact and cost between the two engine types were discussed by literature review and

comparative analysis method. In addition, this study has comprehensively demonstrated the scientific

comparison of the use of hydrogen obtained through green hydrogen production techniques in liquid

fuel rocket engines and the combustion characteristics of hybrid fuel engine technology. Data obtained

from the literature show that hydrogen offers advantages such as high specific impulse (⁓450s),

environmentally friendly combustion products and potential reusability (Turner, 2004; Valenti et al.,

2021; NASA, 2020). However, cryogenic challenges in storing and transporting liquid hydrogen still

represent a significant technical obstacle (Schlapbach & Züttel, 2001). Hybrid engines, on the other

hand, provide operational flexibility with their simple structure, safer storage and controllable

combustion processes (Chiaverini & Kuo, 2007). However, they lag behind liquid hydrogen systems

in terms of specific thrust and efficiency. Advanced combustion data has revealed that the liquid

hydrogen+LOX combination provides approximately 30–40% higher specific thrust compared to

hybrid systems (NASA, 2020). Scientifically, this review highlights the long-term potential of green

hydrogen in sustainable rocket fuel research, revealing how hybrid engine technology balances its

practical benefits in the near term. Findings obtained from relevant references indicate that liquid fuel

engine technologies will become more dominant in space research if the green hydrogen infrastructure

develops. In this respect, the study contributes to the holistic evaluation of sustainable propulsion

systems from engineering and environmental perspectives.