Experimental study on the effects of fuel properties on spray macroscopic characteristics, particle size distribution, and velocity field in a constant volume chamber

With the growing energy crisis, clarifying the effects of fuel properties on the engine spray process is one of the critical researches to find new alternative fuels for engines. In this study, the spray macro characteristics, spray particle size distribution, and spray velocity field of various fuels (diesel/biodiesel/coal-to-liquids/aviation kerosene) in a constant volume chamber under different injection pressures and environmental conditions were studied using a spray visualization test platform. The effects of fuel properties such as density, kinematic viscosity, surface tension, and evaporation characteristics on spray parameters, particle size distributions, and velocity distributions were analyzed. The results showed that the physical properties of the fuels under different evaporation conditions affected the spray process to different degrees. The effect of kinematic viscosity was significant under low evaporation conditions. As the kinematic viscosity decreased, the fuel spread more easily, and the fuel spray velocity distribution was more uniform. The effect of fuel volatility on the spray process was enhanced in the presence of significant evaporation. The effects of spray conditions, environmental conditions, and fuel properties on the spray performance were synthesized, and the expression of SMD with respect to the dimensionless parameters We and Re was obtained. With the increase in We and Re, the kinetic energy of the fuel development increased, the jet was more easily broken, and the fuel was better atomized. The experimental analysis results provided in this study illustrate the influence mechanism of fuel physical properties on the fuel spray process, which can provide theoretical support for the improvement of engine fuel adaptability and can also provide ideas for the development of new fuels.