The Effects of Fuel Temperature on a Spray of a Swirl Type Injector Manufactured for the Use of Direct Injection Gasoline Engines

Fuel temperature in the injector of direct injection gasoline engine is high. On some conditions it exceeds over 410 K. In order to understand spray behavior and mixture processes on these conditions, the effects of fuel temperature on spray characteristics injected by a swirl type injector for direct injection gasoline engines were investigated. In experiments, a constant volume chamber is used to visualize spray and mixture formation processes by LASER sheet, shadow graph and schlieren techniques. In addition Sauter mean radius (SMR) were measured. As these results, increasing fuel temperature over saturated temperature roll up didn't exist, the spray width was narrow and the penetration length was extremely long. Moreover although evaporation occurred quickly, the fuel vapor mixed with the surrounding air incompletely. This is because spray gathered near the nozzle axis and roll up didn't exist.