Quantitative Determination of Slip-length of Liquid Lubricant in Highly Pressurised Non-conformal Contacts

Description

Traction provided by a lubricated conjunction of two relatively moving non-conformal surfaces has a maximum value. This is possibly attributed to the limiting shear strength of the lubricant. Much effort has been put into the study of the high-pressure rheology of liquid lubricant. Recently, another hypothesis has been put forward that the limiting value of traction may be due to the slippage at the liquid/solid interface. Slippage can probably be the dominating factor under certain running conditions such as high sliding, thin lubricating film, and so on. Theoretical studies on the slippage of lubricating contacts have emerged, but there is only very limited, if any, experimental work.This project aims to (i) produce direct evidence of the boundary slippage in lubricated contacts, and (ii) devise a method to quantify the amount of slip, i.e. the slip-length. There is no existing technique to quantify the wall-slippage at the highly pressurized lubricated contacts. This work is thus of considerable academic and practical significance.