Observation on dynamic behavior of droplets evaporation after the end-of-injection of diesel spray

• Main Authors: Nawi, M. A. M., Kidoguchi, Y., Izamshah, R., Kasim, M. S., Khor, C. Y., Jamalludin, Mohd Riduan, Rahim, Wan Mohd Faizal Wan Abd, Rosli, M. U.
• Format: Conference Proceeding
• Language: English
• Subjects: Atomizing; Compression ratio; Cylinders; Diesel engines; Emission analysis; Evaporation; Liquid fuels; Luminous intensity; Nitrogen oxides; Nozzles; Particulate emissions; Rare gases; Recession; Shadowgraph photography
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.5066650

The effect on low temperature in diesel engine has shifted towards lower compression ratios to reduce low nitrogen oxides (NOx) emissions and particulate matter (PM). In addition, lower compression ratios are lower compression temperatures in the cylinder by a start of injection. Since of this aspect, information on liquid fuel of spray began to ignite become one an advantage to comply with stringent legislations of emission vehicles. In the current study, the characteristics of the dynamic behavior of diesel spray at the after the end-of-injection (aEOI) were investigated. The transient of liquid fuel under low temperature has shown a better fuel evaporation, and a mixing process occurred at the aEOI. The dual nano-spark shadowgraph photography method using constant volume spray chamber filled with high density under room temperature inert gas has been applied in this study. The system has two sparks that send high-intensity spark light towards the spray at a short time interval, and then images of the same spray at different timing can be captured on separate still cameras. This observation shows that at the aEOI the liquid fuel concentration has decreased close to the nozzle tip. The tendency of recession that increases to liquid fuel was affected by high ambient density (ρa=25kg/m3) and high injection pressure (Pinj=100MPa) was applied. Based on the characteristics above the liquid fuel has shown an improvement of atomization at the spray center and evaporation greatly promoted at the edge of the spray boundary. Here, the weak boost momentum will lead to the entire structure becoming imperfect spray and spray in a quasi-steady state was formed.