Engine Oil Viscosity Classification Low-Temperature Requirements - Current Status and Future Needs

2009 ◽  
pp. 161-161-21
Author(s):  
JA Spearot
Keyword(s):  
Low Temperature ◽  
Engine Oil ◽  
Current Status ◽  
Oil Viscosity ◽  
Future Needs ◽  
Temperature Requirements

In silico approaches in organ toxicity hazard assessment: current status and future needs in predicting liver toxicity

2021 ◽  
pp. 100187
Author(s):  
Arianna Bassan ◽  
Vinicius M. Alves ◽  
Alexander Amberg ◽  
Lennart T. Anger ◽  
Scott Auerbach ◽  
...  
Keyword(s):  
Hazard Assessment ◽  
In Silico ◽  
Liver Toxicity ◽  
Current Status ◽  
Organ Toxicity ◽  
Future Needs

The Influence of Lubricant Supply Conditions and Bearing Configuration on the Performance of (Semi) Floating Ring Bearing Systems for Turbochargers

2017 ◽  
Author(s):  
Luis San Andrés ◽  
Feng Yu ◽  
Kostandin Gjika
Keyword(s):  
Heat Flow ◽  
Thermal Energy ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Engine Oil ◽  
Large Temperature ◽  
Oil Viscosity ◽  
Supply Pressure ◽  
The Impact ◽  
Bearing System

Engine oil lubricated (semi) floating ring bearing (S)FRB systems in passenger vehicle turbochargers (TC) operate at temperatures well above ambient and must withstand large temperature gradients that can lead to severe thermo-mechanical induced stresses. Physical modeling of the thermal energy flow paths and an effective thermal management strategy are paramount to determine safe operating conditions ensuring the TC component mechanical integrity and the robustness of its bearing system. On occasion, the selection of one particular bearing parameter to improve a certain performance characteristic could be detrimental to other performance characteristics of a TC system. The paper details a thermohydrodynamic model to predict the hydrodynamic pressure and temperature fields and the distribution of thermal energy flows in the bearing system. The impact of the lubricant supply conditions (pressure and temperature), bearing film clearances, oil supply grooves on the ring ID surface are quantified. Lubricating a (S)FRB with either a low oil temperature or a high supply pressure increases (shear induced) heat flow. A lube high supply pressure or a large clearance allow for more flow through the inner film working towards drawing more heat flow from the hot journal, yet raises the shear drag power as the oil viscosity remains high. Nonetheless, the peak temperature of the inner film is not influenced much by the changes on the way the oil is supplied into the film as the thermal energy displaced from the hot shaft into the film is overwhelming. Adding axial grooves on the inner side of the (S)FRB improves its dynamic stability, albeit increasing the drawn oil flow as well as the drag power and heat flow from the shaft. The predictive model allows to identify a compromise between different parameters of groove designs thus enabling a bearing system with a low power consumption.

scholarly journals (Q)SARs to predict environmental toxicities: current status and future needs

2017 ◽  
Vol 19 (3) ◽  
pp. 213-220 ◽  
Author(s):  
Mark T. D. Cronin
Keyword(s):  
Current Status ◽  
Future Needs

An assessment of (Q)SARs to predict acute and chronic ecotoxicity.

Sign in / Sign up

Export Citation Format

Share Document