Lubricated Friction and the Hersey Number.

Area of Science:

• Tribology
• Fluid Dynamics
• Materials Science

Background:

• Measuring and predicting lubrication layer thickness and its effect on friction simultaneously is challenging.
• Existing methods struggle to accurately assess lubrication dynamics in frictional contacts.

Purpose of the Study:

• To experimentally and theoretically investigate rigid-isoviscous lubrication between a plate and a sphere.
• To develop a novel method for simultaneous measurement of lubrication layer thickness and friction.
• To propose a modified Hersey number for predicting lubrication and friction.

Main Methods:

• Utilized a novel inductive sensing technique to measure liquid layer thickness.
• Performed simultaneous friction measurements during lubrication experiments.
• Developed a theoretical hydrodynamic model for liquid flow in the contact area.

Main Results:

• Experimental measurements of layer thickness and friction align with hydrodynamic theory.
• The proposed modified Hersey number successfully rescales data for various geometries and systems.
• The modified Hersey number accurately predicts lubrication layer thickness.

Conclusions:

• Hydrodynamic lubrication principles accurately describe the observed phenomena.
• The modified Hersey number offers a superior alternative to the conventional Hersey number for predicting lubrication and friction.
• This work provides a robust framework for understanding and predicting lubrication in frictional contacts.