Rheology of Dilute Polymer Solutions and Engine Lubricants in High Deformation Rate Extensional Flows Produced by Bubble Collapse

Barrow, M. S.; Brown, S. W. J.; Cordy, S.; Williams, P. R.; Williams, R. L.

Abstract

We report a study of liquid jets formed by the collapse of bubbles under cavitationgenerated pressure waves. Such jets involve an extensional flow which is characterized by high rates of extension, the latter being relevant to considerations of the flow of oils
within dynamically loaded journal bearings. The technique reported here is found to be sensitive to the influence of extremely small concentrations of high molecular weight polymeric additive (xanthan gum). Commercial multigrade oils are also found to exhibit
significantly larger resistance to extensional flow than their Newtonian counterparts and, insofar as the multigrade oils studied here are made viscoelastic by polymer additives, and possess significant levels of resistance to extension, the results provide evidence in support of a mitigating effect of viscoelasticity on cavitation, as mooted by Berker et al.

• Journal Article Type: Article
• Acceptance Date: Jan 1, 2004
• Online Publication Date: May 3, 2004
• Publication Date: May 3, 2004
• Deposit Date: Aug 1, 2016
• Journal: Journal of Fluids Engineering
• Print ISSN: 0098-2202
• Electronic ISSN: 1528-901X
• Publisher: American Society of Mechanical Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 126
• Issue: 2
• Pages: 162
• DOI: https://doi.org/10.1115/1.1667889
• Keywords: Mechanical Engineering; Fluid Flow and Transfer Processes
• Public URL: http://researchrepository.napier.ac.uk/Output/320680