Spray characteristics of alternative fuels in constant volume chamber (comparison of the spray characteristics of LPG, DME and n-dodecane)

It has been recognized that alternative fuels such as dimethyl ether (DME) and liquefied petroleum gas (LPG) have less polluting combustion characteristics than diesel fuel. In this study, such alternative fuels were injected into a high pressure and temperature chamber by means of an electronically controlled common rail injection system to reproduce their charge stratification processes in the engine. Their spray images were taken by using a high-speed video camera and copper-vapor laser to analyze their penetration and evaporation characteristics in comparison with normal-dodecane (n-dodecane) which represent the physical and chemical characteristics as a replacement for diesel fuel. The mixture formation of DME and LPG sprays is faster than that of n-dodecane due to their flash boiling characteristics at high pressures and temperatures.