Abstract
Traditional two-stroke piston engines encounter fuel short-circuiting issues, which result in low fuel efficiency and relatively poor emission performance. The higher viscosity and lower volatility of heavy fuel contribute to increased fuel consumption and poorer emissions as utilized in these engines. This study explored the potential of multiinjector configurations in fuel atomization and evaporation, with a particular focus on semidirect injection technology. The configurations that were presented include a dual-injector configuration for the main scavenging ports and a triple-injector configuration for both the main and auxiliary scavenging ports, which were compared to a single-injector configuration in the auxiliary scavenging port. Additionally, different fuel supply ratios for the triple-injector configuration were investigated in the study. A three-dimensional (3D) numerical computational model for a semidirect injection engine was established to analyze the formation process and distribution of fuel atomization and air–fuel mixture under full load at an engine speed of 6000 rpm. Research indicates that locating the fuel injector closer to the scavenging port can effectively reduce fuel film formation and enhance the vaporization rate while maintaining a relatively high fuel capture rate, thereby leading to a uniform distribution of the air–fuel mixture. At a spray angle of 50 deg, the fuel gasification rate of liquid fuel is remarkably enhanced, attaining a value of 81.6%. Meanwhile, increasing the number of injectors reduces fuel loss and enhances both fuel vaporization and mixture uniformity. The fuel supply ratio of 1:1:1 in the triple-injector configuration for the main and auxiliary scavenging ports is more conducive to fuel atomization and evaporation.
