Asymmetric surface textures decrease friction with Newtonian fluids in full film lubricated sliding contact

Jonathon K. Schuh, Randy H. Ewoldt

Research output: Contribution to journalArticle


Surface texturing can decrease friction in lubricated sliding contact. The majority of existing experimental work has focused on symmetric-depth-profile surface textures. This experimental work examines asymmetric-depth-profile surface textures using gap-controlled experiments with Newtonian fluids on a custom tribo-rheometer setup. Measurements of normal force and shear load are reported as a function of texture geometry, gap height, and bi-directional sliding velocity. This work shows that, in the absence of cavitation, surface texture depth symmetry must be broken to produce normal forces (through viscous effects) for gap-based Reynolds Number up to Reh=ρVhη=1.21. Asymmetric surface textures reduce shear stress and generate normal load, and therefore decrease the effective friction coefficient, which we observe to be smallest for the shallowest texture angle tested, β=5.3°.

Original languageEnglish (US)
Pages (from-to)490-498
Number of pages9
JournalTribology International
StatePublished - May 1 2016



  • Full film lubrication
  • Gap-control
  • Reynolds number
  • Surface textures

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

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