The transient spray from a piezo-electric outwardly opening hollow cone injector was analyzed in a constant pressure chamber via the 2D phase Doppler anemometry (PDA) technique. Measurements were performed at non-reacting conditions at pressure and temperature suitable for gasoline direct injection (GDI) engines. Injection duration time was set to 1.3 ms and two different fuels, namely Haltermann straight run naphtha (HSRN) and J-24 light naphtha (LN), were used. Effects of gas pressure and temperature on spray development were studied for HSRN fuel. Measurements were performed for analysis of droplet velocity development at 25 points about the hollow cone spray edge at three heights at various time delays. Selected measurement locations reveal the different behaviors of droplets inside and outside the spray cone. Complementary liquid penetration length and spray tip velocity measurements were performed at various delays after the start of injection with the high-speed diffused back-illumination (DBI) imaging. Measurements from the two different techniques are compared.​

Jianguo Du is a Ph.D Student from the group of Prof. William Roberts.