Search Results

In recent decades, the importance of emerging alternative fuels has increased significantly as a solution to the problems of global warming and air pollution from energy production. In this context, ammonia (NH3) is seen as a potential option and energy vector that may be able to overcome the technical challenges associated with the use of other carbon-free fuels such as hydrogen (H2) in internal combustion engines (ICE). In this research, a numerical methodology for evaluating the impact of using ammonia as a fuel for spark-ignition ICEs has been developed. A combination of a single-cylinder and multi-cylinder numerical experiments has been performed to identify the main challenges and determine correct engine configuration. In addition, the performance of the engine has been evaluated through standard homologation driving cycles, contrasting it with other alternative propulsion configurations.

Recent studies have shown that the use of highly premixed dual fuel combustion reduces pollutant emissions and fuel consumption in CI engines. The most common strategy for dual fueling is to use two injection systems. Port fuel injection for low reactivity fuel and direct injection for high reactivity fuel. This strategy implies some severe shortcomings for its real implementation in passenger cars such as the use of two fuel tanks. In this sense, the use of a single injection system for dual fueling could solve this drawback trying to maintain pollutant and efficiency benefits. Nonetheless, when single injection system is used, the spray characteristics become an essential issue. In this work the fundamental characteristics of dual-fuel sprays with a single injection system under non-evaporating engine-like conditions are presented.