Abstract
The techniques of measuring fuel concentration and evaporation characteristics in combustion chamber were mostly developed to improve combustion performance and emission characteristics in diesel engine. But, It is necessary to apply these techniques to gasoline and gaseous fuel engines because fuel injection system has been changed from port injection or carburetor type into direct injection to improve emissions and fuel consumption.
LEM (Light Extinction Method) was employed for the analysis of spatial and temporal distribution of fuel. To evaluate fuel evaporati on characteristics according to pressure and temperature, fuels were injected into CVC (Constant Volume Chamber), which has different conditions. And the results from CVC were compared to those of RICEM (Rapid
Induction, Compression and Expansion Machine), which simulate early- and late injection of direct injection engine.
LPG fuel is more affected by temperature and pressure in evaporation characteristics than gasoline, but it is more benefit to direct injection engine in every way such as, fuel distribution, evaporating speed and well wetting reduction, etc.