Investigation on combustion characteristics and gas emissions of a high-pressure direct-injection natural gas engine at different combustion modes

Experimental Investigations of the Hydrogen Injectors on the Combustion Characteristics and Performance of a Hydrogen Internal Combustion Engine

“…Therefore, in the short term, internal combustion engines continue to be the primary source of propulsion [11]. In response to energy shortages [12] and climate change, researchers are actively searching for renewable and clean energy sources, such as natural gas [13], hydrogen [14], biofuels [15], and ethanol [16].…”