The Effect of Shear Rate and Shear Stress on Viscosity Determinations at Low Temperatures for Engine Oils
902091
10/01/1990
- Event
- Content
- The viscosity of engine lubricants was measured at multiple shear rates by a unique Scanning Brookfield apparatus. These oils included both Pumpability Reference Oils (PRO) and a selection of today's commercial multigrade oils. It was found that the viscosity of “flow-limited” oils remained constant when the shear rate decreased. Oils with “air-binding” properties exhibited an increase in viscosity with decreasing shear rate. The magnitude of a change in “slope of the temperature/viscosity profile was found to suggest the degree of air-binding character of an oil.The flow characteristics of PRO 1, 3, 9, 11, and 16 were measured at several shear stresses and temperatures in the Mini-Rotary Viscometer. The Scanning Brookfield technique and the Mini-Rotary Viscometer were found to yield similar results when the shear stress of the Mini-Rotary Viscometer was reduced from 525 to 35 Pascals.
- Pages
- 18
- Citation
- Henderson, K., and Sicking, J., "The Effect of Shear Rate and Shear Stress on Viscosity Determinations at Low Temperatures for Engine Oils," SAE Technical Paper 902091, 1990, https://doi.org/10.4271/902091.