Influence of Shear-Thinning of Polymer-Containing Engine Oils on Friction at the Piston Ring-Cylinder Liner Interface

Tamura, Kazushi; Kasai, Moritsugu; Nakamura, Yasuto; Enomoto, Tomoyuki

doi:10.4271/2013-01-2567

Cited by 4 publications

(12 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We calculated the dead center friction force (F DC ) as follows: (1) We then calculated the friction energy per cycle by determining the piston position, Y, as a function of crank angle θ using a standard piston motion equation, as follows: (2) where R is the crank radius and L is the connecting rod length. TDC and BDC corresponds to θ = 0° and θ = 180°, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…The densities, kinematic viscosities, and viscosity indices of these oils were measured by the procedures determined by ASTM D4052, ASTM D445, and ASTM D2270, respectively. This base formulation corresponds to the oil named "#20" in our previous study [2]. …”

Section: Base Formulationmentioning

confidence: 99%

“…We evaluated ring-liner friction using a floating liner-type friction tester that was described previously [2]. This tester was developed in-house for research purposes and consisted of a reciprocating four-ring piston driven by a three-phase induction motor through a crank mechanism (Table 2 and Figure 1).…”

Section: Experimental Devicementioning

confidence: 99%

“…Thus, in addition to the fundamental lubrication parameters (i.e., viscosity of interfacial media, sliding velocity, and normal load), ring-liner friction could also depend on the chemical feature of the ring-liner interface. Our previous study on the relationships between the viscometric properties of engine oils and ring-liner friction [2] revealed that the addition of viscosity modifiers-the polymeric additives frequently used in fuel economy engine oils-caused strong shear-thinning at the ring-liner interface and that the shear rate was estimated to be approximately 10 7 s −1 . This means that in mixed-and boundary-lubrication regimes, viscosity modifiers potentially increase frictional loss and wear probability.…”

Section: Introductionmentioning

confidence: 99%

“…We used several friction modifiers (FMs), including molybdenum dithiocarbamate (MoDTC) and nonmetallic fatty compounds, to modify the boundary lubrication performance of engine oils. To evaluate the effects of FMs on friction, we used a floating liner friction tester, which is widely used to directly measure ring-liner friction [2,3,4,5,6]. The floating liner friction measurements show that friction force at dead center and friction energy per cycle highly depend on FM formulation at high temperatures.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Impact of Boundary Lubrication Performance of Engine Oils on Friction at Piston Ring-Cylinder Liner Interface

Tamura¹,

Kasai²,

Nakamura³

et al. 2014

SAE Int. J. Fuels Lubr.

Self Cite

View full text Add to dashboard Cite

To explore the measures that can be used to improve the fuel economy of internal combustion engines, we investigated how friction at the piston ring-cylinder liner interface is influenced by the boundary lubrication performance of engine oils. We formulated several engine oils with varying boundary lubrication performance and tested them for ring-liner friction by using a floating liner friction tester. We used friction modifiers (FMs) to modify the boundary lubrication performance of engine oils. We found that ring-liner friction is well correlated with the friction coefficients in boundary lubrication regimes when measured by a laboratory friction tester. We also found that the impact of the boundary lubrication performance of engine oils was emphasized in low viscosity engine oils. It makes it possible for improved boundary lubrication performance to inhibit or overcome the viscosity reduction-induced increase of friction energy. These results suggest that FM formulation is as important as viscosity modification for next-generation engine oils to achieve better fuel economy.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Base Formulationmentioning

confidence: 99%

Section: Experimental Devicementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Impact of Boundary Lubrication Performance of Engine Oils on Friction at Piston Ring-Cylinder Liner Interface

Tamura¹,

Kasai²,

Nakamura³

et al. 2014

SAE Int. J. Fuels Lubr.

Self Cite

View full text Add to dashboard Cite

show abstract

A Critical Review of Approaches to the Design of Floating-Liner Apparatus for Instantaneous Piston Assembly Friction Measurement

et al. 2021

View full text Add to dashboard Cite

Several approaches have been developed to measure instantaneous friction between the piston assembly and cylinder in internal combustion (IC) engines, such as floating-liner, reciprocating liner, instantaneous mean effective pressure (IMEP), fixed sleeve, and (P-ω) method and tribological bench tests. However, the “floating-liner method” and the “(IMEP) method” are the most common methods used to measure instantaneous friction between the piston assembly and IC engines. This paper critically evaluates different approaches to the design of the “floating-liner”. The paper begins by discussing piston assembly frictional losses and their significance and then discuss the development of instantaneous piston-friction measurements. After that, it reviews the main design challenges in the floating-liner approach. “Methods of cylinder sealing” and “force balancing methods” are also reviewed. Design challenges associated with firing operation were presented. Floating-liner designs were classified into different categories with a detailed presentation of the features of each. The paper ends by presenting a range of broad recommendations for further work which would benefit future designs.

show abstract

Advantages and Challenges for Low Viscosity Oils in Emergent Countries

Galvão

Tomanik

Fujita

et al. 2017

SAE Technical Paper Series

View full text Add to dashboard Cite

Influence of Shear-Thinning of Polymer-Containing Engine Oils on Friction at the Piston Ring-Cylinder Liner Interface

Cited by 4 publications

References 11 publications

Impact of Boundary Lubrication Performance of Engine Oils on Friction at Piston Ring-Cylinder Liner Interface

Impact of Boundary Lubrication Performance of Engine Oils on Friction at Piston Ring-Cylinder Liner Interface

A Critical Review of Approaches to the Design of Floating-Liner Apparatus for Instantaneous Piston Assembly Friction Measurement

Advantages and Challenges for Low Viscosity Oils in Emergent Countries

Contact Info

Product

Resources

About