Recent fuel economy and stringent emissions concerns have stimulated the use of hydrogen in internal combustion engines and to drive dual‐fuel benefits. This paper explicitly conducted a bibliometric study of scholarly articles on hydrogen enrichment of diverse fuels in compression and spark ignition (SI) engines with dual injection systems (DIS). Bibliographic data of publications (from 2000 to 2024) on this subject were extracted, refined, and analyzed using CiteSpace and VOSviewer. Publication counts and trends, leading disciplines and sponsors, most important journals and articles, most used keywords, and most productive authors, institutions, and countries were explored. The trend, hotspots, and future research on hydrogen‐enriched fuels deployment in SI and compression ignition (CI) engines with DIS as they influence combustion, emissions, and performance were discussed. A total of 526 scholarly articles were relevant to this study, 76% of which were journals. Energy is the most involved academic discipline, while hydrogen is the most used keyword. China, Sathyabama Institute of Science and Technology, International Journal of Hydrogen Energy, and Ji Changwei were the most prolific country, institution, journal, and author, respectively. Additionally, the work of Bauer and Forest (2001) is the most prominent as it attracted the highest number of citations. Research hotspots center on the combustion and performance of CI engines fueled with hydrogen‐diesel blends and the performance and emissions of SI engines powered with hydrogen‐gasoline and hydrogen‐methane. Future studies involved the utilization of advanced combustion technologies, emissions reduction techniques, and novel hydrogen‐enriched fuels to examine the emissions, combustion, acoustics, cycle–cycle variations, vibration, and performance profiles of dual injection CI and SI engines to promote cleaner fuels to decarbonize the global transport sector. Finally, this study provides state‐of‐the‐art documentation on DIS and hydrogen‐enriched fuels application in SI and CI engines for the engine research community.
Giwa et al. (Thu,) studied this question.