Nozzle geometry influence on the diesel spray combustion

The current work describes an experimental activity conducted on single-hole diesel injectors (0.100 mm) with different k-factor (k0 and k1.5) spraying in a constant volume combustion vessel. Injection pressures 70, 120 and 180 MPa, ambient gas density of 23.9 kg/m3 and temperature of 900 K were investigated. Conditions of 0% and 15% of O2 were tested varying the gas mixture composition (N2, C2H2, H2, O2). Ultra-low sulfur diesel (ULSD) was used as fuel. Schlieren imaging were performed using a high-speed camera and a pulsed-wave led system to track both liquid and vapor phases of the combusting spray. The paper will present the influence of different k-factor nozzle on the measurements of liquid and vapor penetration, ignition delay, and lift-off length for several experimental conditions. Moreover, fuel injection rates measurements were carried out using a meter working on the Bosch tube principle to characterize the injected mass.