Study on the Effects of Nozzle Fuel Spray Pattern on Cetane Number Measurement as Determined in the Ignition Quality Tester (IQT™)

The spatial distribution of drops in sprays is critical to the performance of many atomization systems, including diesel engine injectors, gas turbine injectors, spray coating systems, and furnace burners. This paper presents an investigation of the effects of nozzle fuel spray pattern on the measurement of cetane number as determined in the Ignition Quality Tester (IQT™). To determine the effects of spray pattern on cetane number, an optical spray pattern test rig was developed. The test rig was comprised of the IQT™ fuel injection system and data acquisition system, and the Optical Spray Pattern Analyzer from Nexum. Several nozzles from different manufacturers where chosen for this study. Cetane numbers for a diesel reference fuel were obtained for each of the test nozzles in the IQT™ and where compared qualitatively to spray pattern images for each of the test nozzles observed from the spray pattern test rig. As a result, a typical evolution of the spray pattern across the main injection was identified; however the spray pattern did not appear to have any noticeable effect on the cetane number as measured in the IQT™.