Friction is a complex subject that we have broken up into multiple modules in this course. Understanding friction is critical in wide-ranging applications, from automotive and aerospace, to rock climbing and curling. In many cases we try to minimize friction (to improve engine performance, for example), but in other cases a high degree of friction is essential (in brake systems, for example). The concepts have been studied since antiquity, and we continue to invest a great deal of effort and resources to understand and control friction today.

To understand friction in lubricated systems we need to look at the complex relationships between film thickness, temperature, pressure, materials, surface texture and more. In this module we discuss the basic mechanisms and physics of lubricated friction and how it is calculated. We look at the relationships between surface texture (surface roughness) and lubricated friction, introducing the concepts of hydrodynamic, elastohydrodynamic, mixed and boundary regimes and how friction and lubrication differ in these regimes. Finally, we look at the mechanics of lubrication with help from a short video from Vern Wedeven (used with permission), who has written a number of excellent books on this topic as well.

Following this module we encourage you to watch the modules on Dry Friction and Rolling Friction for a more complete view of friction.

This is Module 6 of the Surface Texture and Tribology Short Course. The full course is available on udemy, or you can select the individual course modules of interest to you. Enter "surface roughness texture tribology" in the udemy search bar to browse the full course and modules.