TY - JOUR

T1 - Effect of Freeform Honing on the Geometrical Performance of the Cylinder Liner - Numerical Study

AU - Alshwawra, Ahmad

AU - Pohlmann-Tasche, Florian

AU - Stelljes, Frederik

AU - Dinkelacker, Friedrich

N1 - Funding Information: A partial fund for this work was provided by the German Federal Ministry for Economic Affairs and Energy (BMWi) within the cooperation project “Energieeffiziente Prozessketten zur Herstellung eines reibungs-, gewichts-und lebendsdaueroptimierten Antriebsstrangs” (Antriebsstrang 2025). The German Jordanian University (GJU) funded another part through a research scholarship. 1

PY - 2022/9/1

Y1 - 2022/9/1

N2 - Reducing the friction of the internal combustion engine (ICE) is of major interest to reduce fuel consumption and greenhouse gas (GHG) emissions. A huge potential for friction reduction is seen in the piston ring-cylinder liner (PRCL) coupling. Approaching the cylindrical liner shape in the hot operation state will enhance the PRCL conformation. Recently, newly developed freeform honing techniques can help to achieve this perfect cylinder shape. This article presents a numerical study of the effect of freeform honing on the geometrical performance of the liner in the hot operation state. The freeform honed liner (TR) concept is based on the approach of reversing the local deformation of a conventional circular liner. A validated computational model for a gasoline engine is used to compare the geometrical performance of those TR cases with circular, elliptical (EL), and conical elliptical liners (NEL) at different operational points. It was found that the TR concept can reduce the roundness error by 92-95% and the straightness error by 70-75% when the reference load equals the operational one. Quite a good compromise is found to be the initial NEL shape, which probably would be easier for the manufacturing process. In this study, the influence of the reference load on the shape, and with that on friction, is also investigated at different operational loads. It was found that the reference load should be selected at a medium level since commonly the deviations at higher operational loads are less problematic for friction than vice versa. The numerical studies with optimal freeform-shaped cylinder liners - or with the compromise of NEL shapes - show a promising approach to enhance the PRCL conformation and reduce engine friction.

AB - Reducing the friction of the internal combustion engine (ICE) is of major interest to reduce fuel consumption and greenhouse gas (GHG) emissions. A huge potential for friction reduction is seen in the piston ring-cylinder liner (PRCL) coupling. Approaching the cylindrical liner shape in the hot operation state will enhance the PRCL conformation. Recently, newly developed freeform honing techniques can help to achieve this perfect cylinder shape. This article presents a numerical study of the effect of freeform honing on the geometrical performance of the liner in the hot operation state. The freeform honed liner (TR) concept is based on the approach of reversing the local deformation of a conventional circular liner. A validated computational model for a gasoline engine is used to compare the geometrical performance of those TR cases with circular, elliptical (EL), and conical elliptical liners (NEL) at different operational points. It was found that the TR concept can reduce the roundness error by 92-95% and the straightness error by 70-75% when the reference load equals the operational one. Quite a good compromise is found to be the initial NEL shape, which probably would be easier for the manufacturing process. In this study, the influence of the reference load on the shape, and with that on friction, is also investigated at different operational loads. It was found that the reference load should be selected at a medium level since commonly the deviations at higher operational loads are less problematic for friction than vice versa. The numerical studies with optimal freeform-shaped cylinder liners - or with the compromise of NEL shapes - show a promising approach to enhance the PRCL conformation and reduce engine friction.

KW - Conical liner

KW - Cylinder liner

KW - Engine design

KW - Freeform honed liner

KW - Non-circular liner

KW - Piston ring-cylinder liner conformation

KW - Tapered bore liner

KW - Thermal deformation

UR - http://www.scopus.com/inward/record.url?scp=85139201840&partnerID=8YFLogxK

U2 - 10.4271/03-16-04-0027

DO - 10.4271/03-16-04-0027

M3 - Article

AN - SCOPUS:85139201840

VL - 16

JO - SAE International Journal of Engines

JF - SAE International Journal of Engines

SN - 1946-3936

IS - 4

M1 - 03-16-04-0027

ER -