Effects of mixture formation strategies on combustion in dual-fuel engines - a review

The article presents an overview of technical solutions for dual fuel systems used in internal combustion engines. It covers the historical and contemporary genesis of using two fuels simultaneously in the combustion process. The authors pay attention to the value of the excess air coefficient in the cylinder, as the ignitability of the fuel dose near the spark plug is a critical factor. The mixture formation of compression ignition based systems are also analyzed. The results of research on indirect and direct injection systems (and their combinations) have been presented. Research sections were separated based to the use of gasoline with other fuels or diesel oil with other fuels. It was found that the use of two fuels in different configurations of the fuel supply systems extends the conditions for the use of modern combustion systems (jet controlled compression ignition, reactivity controlled compression ignition, intelligent charge compression ignition, premixed charge compression ignition), which will enable further improvement of combustion efficiency.