ME 3320 Lecture Notes - Lecture 99: Lubricant, Shear Rate, Newtonian Fluid

• School: Baylor University
• Department: Mechanical Engineering
• Course: ME 3320
• Professor: Terrell

Document Summary

Week 9 lecture (part 2) - lubrication regimes. Lubrication regimes: boundary lubrication occurs at low speeds or high loads. Applied load between surfaces s partially supported by the lubricant film, and partially supported by asperities. Boundary lubrication characteristics of lubricant can be improved via specialized additives (additives are generally chemical in nature, protects surfaces: elastohydrodynamic lubrication (ehl) Higher sliding speed, and lubricant can support load. Pressure of lubricant film is so large, it causes the surface elements to elastically deform. Occurs at moderate sliding speeds and high loads: hydrodynamic lubrication (aka full film lubrication ) A full lubricant film fully separates the two surfaces, minimizing friction and wear h = film thickness. Hydrodynamic lubrication occurs at high speeds and/or low loads. If you increase viscosity, increases the lubricant"s ability to hold the load. Countereffect is the weight. (fluid film lubrication is decreased with the w. )