Effect of Oil Film Distribution in the Concave Created by Piston Skirt Profile or Pattern Coating on Skirt Friction Loss

Takuro Nakagawa･Kenta Sato･Hisanobu Kawashima･Hidekazu Suzuki･Tsuneaki Ishima (Gunma University)

The friction reduction effect of concavities created by piston skirt profile or pattern coating on the piston skirt was investigated. Based on the results of oil film visualization, calculations were carried out assuming that there was insufficient quantity of oil in the concavities. Friction loss increased when there was no oil in the concavities. It was found that when there was oil in a part of the concavities, the friction loss was lower compared with the condition where the concavities was completely filled with oil.

MBD Tool Development for Piston Ring Performance Prediction
-1D-CAE Model for Lubricating Oil Consumption-

Hikaru Chiba･Kazuya Mochizuki･Itsuro Suzuki･Masaru Yazawa･Naoki Iijima (RIKEN/NPR-RIKEN)

MBD (Model Based Development) tool was developed to reduce engine development costs. It is enable to predict oil consumption, blow-by, and friction force on various piston ring specification. In particular, oil consumption simulation were applied statistical methods and experimental coefficients obtained by oil visualization in glass cylinder. As a result, 1D-CAE model for oil consumption was generated. The characteristics are to predict quickly with higher accuracy. In this paper, effectivity of the model is shown by verification on various test condition.

Effect of Engine Oil Containing Nanobubbles by Ultrafine Pore Method on Reduction of Friction Loss in Piston System
-Correlation between the Generation Density of Nanobubbles and Friction Reduction Effect-

Kai Horiba･Masaya Fukuda･Shusuke Hoshino･Takumi Iwata･Masakuni Oikawa･Yuji Mihara (Tokyo City University)

The effect of nanoscale bubbles generated in engine oil by the ultrafine-pore method on friction work between piston and cylinder was investigated by measuring friction force in a floating liner engine. In this study, the correlation between the bubble generation density and the friction reduction effect was confirmed, especially by changing the surface area of the generating part of the nanobubble generator.

Development of an Evaluation Method that can Quantify the Effect of Fuels and Lubricants on Gasoline Engines

Shouta Tobe･Masami Shiki･Akihiro Suzuki･Naoki Eguchi･Kohei Hashimoto (SUBARU)

There are multiple methods for evaluating carbon deposits that simulate the environment inside the engine. However, it is not possible to quantitatively compare all the environmental effects used by the engine.　Therefore, in this study, we development a method to quantitatively evaluate the degree of impact of fuel and lubricant by simulating the usage environment.

Strategies for Application-Specific Fuel Economy Engine Oil Solutions

Field Sam･Anderson William B.･Engelman Kristi･Bell Ian･Hidetaka Hoshino (Afton Chemical)

This paper analyses the real-world operation of a common North American engine platform through chassis-dyno testing and compares it with the output of a simulation-based digital twin. The results from the chassis-dyno evaluation are then compared with industry-standard fuel economy test methods, evaluating their relevance for inclusion in fuel economy-driven engine oil specifications, particularly in the context of hybrid powertrains.