From a Chevron Phillips Faq
http://www.cpchem.com/enu/pao_f_faq16.asp
Q: The fluids I design are subjected to various shear and temperature conditions. Can PAOs help me balance the protection and energy conservation requirements in my equipment?
A: You bet! PAOs are Newtonian fluids, in other words their viscosities are fairly independent of shear rate. As fluids flow throughout the equipment, they travel through various lubrication regimes and shear environments resulting in viscosity changes for non-Newtonian fluids. The effects of the shear rate differences are even more exaggerated at low temperature startup conditions, when the lubricant function is critical for equipment protection.
The chart below shows the effect of two different shear rate viscosity determinations on three different fluids (4 cSt at 100°C) and the dramatic differences between them. The tests used below were the Cold Cranking Simulator for high shear (about 10-5 sec-1) and Brookfield viscosity for low shear (about 2 sec-1) each measured at -20°C.
Fluids are typically subjected to various shear and temperature conditions. As the chart above clearly demonstrates, the difference in viscosity as a function of shear rate is magnified as temperature decreases. PAOs help to balance the protection and energy conservation requirements in equipment because they are more Newtonian than mineral oils. Understanding this advantage is important for optimizing the performance of today’s fluids and improving the life of equipment.
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My question is mainly due to my reading above my knowledge level. Does this mean that oils formulated with PAO do not suffer permanent viscosity loss as a result of shear rate?
http://www.cpchem.com/enu/pao_f_faq16.asp
Q: The fluids I design are subjected to various shear and temperature conditions. Can PAOs help me balance the protection and energy conservation requirements in my equipment?
A: You bet! PAOs are Newtonian fluids, in other words their viscosities are fairly independent of shear rate. As fluids flow throughout the equipment, they travel through various lubrication regimes and shear environments resulting in viscosity changes for non-Newtonian fluids. The effects of the shear rate differences are even more exaggerated at low temperature startup conditions, when the lubricant function is critical for equipment protection.
The chart below shows the effect of two different shear rate viscosity determinations on three different fluids (4 cSt at 100°C) and the dramatic differences between them. The tests used below were the Cold Cranking Simulator for high shear (about 10-5 sec-1) and Brookfield viscosity for low shear (about 2 sec-1) each measured at -20°C.
Fluids are typically subjected to various shear and temperature conditions. As the chart above clearly demonstrates, the difference in viscosity as a function of shear rate is magnified as temperature decreases. PAOs help to balance the protection and energy conservation requirements in equipment because they are more Newtonian than mineral oils. Understanding this advantage is important for optimizing the performance of today’s fluids and improving the life of equipment.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >
My question is mainly due to my reading above my knowledge level. Does this mean that oils formulated with PAO do not suffer permanent viscosity loss as a result of shear rate?
