Lubrication by a smectic liquid crystal

Technical Report · Thu Oct 01 04:00:00 EDT 1987

OSTI ID:5777084

Fischer, T E; Bhattacharya, S; Salher, R; Lauer, J L; Ahn, Y J

The hydrodynamic aspects of lubrication by the smectic A liquid crystal octylcyanobiphyenyl (8CB) were investigated in a thrust bearing and in the concentrated ball on flat contact. Both bearings were run with a Newtonian mineral basestock for comparison and performed as expected; friction followed the Stribeck curve in the thrust bearing and the film thickness increased with (velocity) 2/3 in the elastohydrodynamic lubrication of the point contact. The lubricating behavior of the smectic liquid crystal is qualitatively different from that of the Newtonian fluid. Curves of friction coefficient vs. velocity x viscosity/load cannot be superimposed to form a Stribeck curve. The higher the load, the lower the velocity at which low friction is maintained, which is opposite to the behavior of Newtonian fluids. In concentrated contact (EHD lubrication) the smectic gives a friction coefficient that is constant with velocity and lower than the minimum value with the Newtonian fluid. The fluid film thickness varies with (velocity) 1/2.

• Research Organization: Rensselaer Polytechnic Inst., Troy, NY (USA). Dept. of Mechanical Engineering
• OSTI ID: 5777084
• Report Number(s): AD-A-206120/8/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
42 ENGINEERING
420500 -- Engineering-- Materials Testing
AROMATICS
BEARINGS
CRYSTALS
CYANIDES
DIMENSIONS
FILMS
FLUID MECHANICS
FLUIDS
FRICTION
HYDRODYNAMICS
HYDROXY COMPOUNDS
LIQUID CRYSTALS
LIQUIDS
LUBRICANTS
LUBRICATION
MECHANICS
MINERALS
ORGANIC COMPOUNDS
PHENOLS
THICKNESS