relation: https://khub.utp.edu.my/scholars/10034/ title: Investigation of puffing and micro-explosion of water-in-diesel emulsion spray using shadow imaging creator: Ismael, M.A. creator: Heikal, M.R. creator: Aziz, A.R.A. creator: Crua, C. creator: El-Adawy, M. creator: Nissar, Z. creator: Baharom, M.B. creator: Zainal, E.Z.A. creator: Firmansyah description: Water-in-diesel emulsions potentially favor the occurrence of micro-explosions when exposed to elevated temperatures, thereby improving the mixing of fuels with the ambient gas. The distributions and sizes of both spray and dispersed water droplets have a significant effect on puffing and micro-explosion behavior. Although the injection pressure is likely to alter the properties of emulsions, this effect on the spray flow puffing and micro-explosion has not been reported. To investigate this, we injected a fuel spray using a microsyringe needle into a high-temperature environment to investigate the droplets' behavior. Injection pressures were varied at 10 v/v water content, the samples were imaged using a digital microscope, and the dispersed droplet size distributions were extracted using a purpose-built image processing algorithm. A high-speed camera coupled with a long-distance microscope objective was then used to capture the emulsion spray droplets. Our measurements indicated that the secondary atomization was significantly affected by the injection pressure which reduced the dispersed droplet size and hence caused a delay in puffing. At high injection pressure (500, 1000, and 1500 bar), the water was evaporated during the spray and although there was not enough droplet residence time, puffing and micro-explosion were clearly observed. This study suggests that high injection pressures have a detrimental effect on the secondary atomization of water-in-diesel emulsions. © 2018 by the authors. publisher: MDPI AG date: 2018 type: Article type: PeerReviewed identifier: Ismael, M.A. and Heikal, M.R. and Aziz, A.R.A. and Crua, C. and El-Adawy, M. and Nissar, Z. and Baharom, M.B. and Zainal, E.Z.A. and Firmansyah (2018) Investigation of puffing and micro-explosion of water-in-diesel emulsion spray using shadow imaging. Energies, 11 (9). ISSN 19961073 relation: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053884627&doi=10.3390%2fen11092281&partnerID=40&md5=ac13cd5820d9bbc5a74e2724d9c4a8aa relation: 10.3390/en11092281 identifier: 10.3390/en11092281