Deformation Behavior of Thin Lubricant Films at Elevated Pressure-Viscometric Functions.

Abstract

Although normal stress differences in liquids have conventionally been associated with polymers, aspects of rheological behavior in lubricated concentrated contacts suggest that normal stress difference may be significant in even low molecular weight liquids sheared under high pressure and high shear stress. A torsional flow rheogoniometer was constructed for use at high (300 MPa) pressure. Four typical liquid lubricants were investigated, including one polymer/mineral oil solution. Shear stress and N1- N2 are reported as functions of shear rate. The effect of pressure variation is reported for two liquids. Results are compared with predictive techniques and a molecular dynamics simulation. Simple low molecular weight lubricant base oils can generate measurable and significant normal stress differences when sheared at high shear stress. (AN)

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1996
Accession Number
ADA303479

Entities

People

  • Scott Bair

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Constitutive Equations
  • Couette Flow
  • Engineering
  • Equations
  • Friction
  • High Pressure
  • Lubricants
  • Lubrication
  • Materials
  • Measurement
  • Mechanical Engineering
  • Mechanics
  • Molecular Dynamics
  • Molecular Weight
  • Shear Bands
  • Shear Stresses
  • Tribology

Readers

  • Materials Science and Engineering.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).