City Research Online

Effect of viscosity and temperature on in-nozzle flow and cavitation in a multi-hole injector

Nouri, J. M., Mackenzie, S., Gaskell, C. & Dhunput, A. (2012). Effect of viscosity and temperature on in-nozzle flow and cavitation in a multi-hole injector. Paper presented at the Fuel Systems for IC Engines, 14-3-2012 - 15-3-2012, IMechE, London, England.


Two 3-D six-hole transparent enlarged model injector have been manufactured with full optical access; both were 15 times larger than the real size, but one had a length-to-diameter ratio twice as the second one. The working fluid was water and aqueous solutions of glycerol circulating through the nozzle injector under steady- state flow conditions at different flow rates, pressures and needle lift positions. Real-time in-nozzle flow visualisations were obtained using a high speed video recorder which allowed determination of in-nozzle flow patterns, in particular, formation, dynamics and the development of cavitation.

Simultaneous imaging of the flow inside the nozzle injector showed that reducing the needle lift would suppress the cavitation intensity in both models especially during early stage of cavitation causing a delay on its onset from a CN ≈ 1.1 at full lift to CN = 1.9 at 25% of the full. The main noticeable effect of L/D was found to be at the exit of the nozzles where different types of in-nozzle flow would be experienced due to different length of the nozzles with larger L/D having a more developed and stable cavitating flow and is expected to affect spray outside the nozzles. The effect of viscosity was only evident during early stage of cavitation with a delay on the onset of the cavitation and a less intense cavitation with blends at higher viscosities. The results also showed that an increase in temperature had the effect of enhancing cavitation due to lower viscosity and weaker molecular bounding.

Publication Type: Conference or Workshop Item (Paper)
Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics
Departments: School of Science & Technology > Engineering
[thumbnail of IMechE 14-15 March 2012_JMN.pdf] Text - Accepted Version
This document is not freely accessible due to copyright restrictions.


Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email


Downloads per month over past year

View more statistics

Actions (login required)

Admin Login Admin Login