Development Trend of Liquid Hydrogen-Fueled Rocket Engines (Part 2: Core Technologies)

Hydrogen is widely used in various industries due to its high performance attributed to high calorific value per unit mass, low molecular weight, and potentially zero emissions. Additionally, many hydrogen engine systems have been developed since the 1960s due to their high performance. However, there are some challenges in operating hydrogen-fueled engine systems and developing core technologies that must be equipped to solve them. Therefore, countries operating such systems have been conducting various studies to improve the technologies. This paper reviews the core technologies required to operate a hydrogen engine and the research performed on each technology. A new material or method was used to develop the technology. Furthermore, experiments, such as lab-scale and full-scale, modeling techniques, and computational fluid dynamics (CFD) analysis, were performed to confirm the effect. It is expected to help identify and secure element technologies for the future development of hydrogen-fueled engine systems.