The atomization current and droplet size of ethanol in two different small-scale electro-spraying systems

Gan, Yunhua; Zhang, Xia; Li, Haige; Tong, Yang; Shi, Yanling; Yan, Yuying

Abstract

An experimental study on electro-spraying from small-scale combustors is carried out using liquid ethanol as fuel. Two systems of electro-spraying are employed in the present study; one is a nozzle system (without a ring electrode) and the other is a nozzle-ring system (with a ring electrode). The photos of electro-spraying at the cone-jet mode are taken by a digital camera. The voltage drop across the resistance in the loop is measured by a data acquisition instrument, and the atomization current is calculated according to Ohm's Law. The size and velocity of electro-spraying droplets are measured by a Phase Doppler Anemometer. A non-dimensional analysis on atomization current is completed to explain the electro-spraying phenomena of liquid at the stable cone-jet mode. The results show that, the lower atomization current and droplet velocity corresponds to smaller size of droplet. Based on the results of non-dimensional analysis, it is found that the dimensionless atomization current in both the nozzle system and nozzle-ring system obeys the scaling law as square root of the dimensionless flow rate. The charge density is of a −1.5 power dependence on droplet diameter. Both of the nozzle and the nozzle-ring systems show a good agreement with Rayleigh instability.

Citation

Gan, Y., Zhang, X., Li, H., Tong, Y., Shi, Y., & Yan, Y. (2017). The atomization current and droplet size of ethanol in two different small-scale electro-spraying systems. Journal of Electrostatics, 87, https://doi.org/10.1016/j.elstat.2017.05.003

• Journal Article Type: Article
• Acceptance Date: May 5, 2017
• Online Publication Date: May 17, 2017
• Publication Date: Jun 1, 2017
• Deposit Date: May 30, 2017
• Publicly Available Date: Nov 18, 2018
• Journal: Journal of Electrostatics
• Print ISSN: 0304-3886
• Electronic ISSN: 0304-3886
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 87
• DOI: https://doi.org/10.1016/j.elstat.2017.05.003
• Keywords: Cone-jet mode; Electro-spraying; Atomization current; Droplet size; Droplet velocity; Non-dimensional analysis
• Public URL: https://nottingham-repository.worktribe.com/output/968378
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0304388617300104
• Contract Date: May 30, 2017