Predictive Piston Cylinder Unit Simulation - Part I: Novel Findings on Cyclic Inter-Ring Pressure Measurements and Piston Ring Dynamic Simulation Validation

Koeser, Philipp S.; Berbig, Frank; Pohlmann-Tasche, Florian; Pasligh, Henning; Dinkelacker, Friedrich

doi:10.4271/2021-01-0650

Cited by 5 publications

(3 citation statements)

References 29 publications

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“…In the laboratory at Leibniz University Hannover, a Floating-Liner single-cylinder test rig has been built up in recent years for detailed friction force measurements based on a commercial vehicle engine with a 130 mm bore with basic parameters given in Table 1 [25][26][27][28]. The Floating-Liner method is a direct measurement method for determining the frictional force between the piston assembly and cylinder liner.…”

Section: Experimental Setup 21 Floating-liner Testbenchmentioning

confidence: 99%

Experimental Investigation of a Free-Form Honed Cylinder Liner for Heavy-Duty Engines

Stelljes,

Pohlmann-Tasche,

Dinkelacker

2024

Lubricants

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For future internal combustion engines, driven by regenerative fuels, efficiency is more important than ever. One approach to reduce the losses inside the piston cylinder unit (PCU) is to improve the alignment of the liner and the piston. Therefore, a cylinder liner with a free form was developed at the Institute of Technical Combustion (ITV) of the Leibniz University Hannover which compensates radial and linear deformations along the stroke. The layout is based on a FEM simulation. The liner was manufactured by the Institute of Production Engineering and Machine Tools (IFW) of Leibniz University of Hannover with a novel turn-milling process. The liner was investigated on the heavy-duty Floating-Liner engine of ITV with a displacement of 1991 ccm and a bore diameter of 130 mm. The experimental results show improvement in the friction losses over the whole engine map in the range of 9% and up to 17.3% compared to a serial liner. Sealing efficiency could be improved up to 28.8%, depending on the operational point. Overall, the investigation aims for lower fuel consumption which would in result fewer emissions.

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Section: Experimental Setup 21 Floating-liner Testbenchmentioning

confidence: 99%

Experimental Investigation of a Free-Form Honed Cylinder Liner for Heavy-Duty Engines

Stelljes,

Pohlmann-Tasche,

Dinkelacker

2024

Lubricants

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“…6 The inter ring pressure directly above the oil control ring as result of the compression/expansion gasses that bypass the top rings and crankcase pressure on the lower face result in a negligible change in radial forces of the threepiece oil Control Ring due to their diminutive magnitude and thin axial cross section of the oil control ring segments. [7][8][9] Extensive modelling and experimental research have been conducted regarding piston compression rings, 10 however, proportionally less consideration has been given to three-piece oil control rings. Of the three types of oil control ring, the single piece twin land oil control rings (6625 type 5 ) and twopiece twin land oil control rings (6626 type 5 ) have been the major focus of research.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An experimental investigation of low viscosity lubricants on three piece oil control rings cylinder liner friction

Forder

Morris

King

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part J:

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Reducing energy use and improving engine efficiency is a complex task however to date a continued reduction of lubricant viscosity has proved effective. Reducing viscosity decreases hydrodynamic friction and pumping losses however it can also exacerbate boundary friction losses. Detailed and representative component level experimentation is required to understand the effects of viscosity reduction on friction and opportunity for further optimisation. This paper presents a novel motored reciprocating Tribometer which has been developed to measure the friction between complete cylinder liners and three-piece oil control rings. The system holds individual or multiple rings stationary in a bespoke ring holder and reciprocate the cylinder liner thereby replicates the relative kinematics of the components in service. The new design has many operational advantages to identify and benchmark the individual contribution of oil control ring friction including near total isolation of oil ring-cylinder liner bore conjunction, pure rectilinear motion and use of full components without resorting to split liner/ring geometries. The experimental rig is used to measure friction at the three-piece oil control ring- cylinder liner conjunction when lubricated with two low viscosity lubricants. The results show prevalence of mixed regime lubrication across the speeds, temperatures and lubricants investigated. The oil control ring under investigation is shown to operate in mixed regime lubrication and at cold start the introduction of lower viscosity lubricants such as 0W-8 showed higher level of oil control ring-cylinder liner friction in comparison to the 0W-40. The information and experimental facility are of critical use for engine designers when considering the potential contradictory component efficiency behaviour when moving to ultra-low viscosity lubricants.

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Hybrid digital twin for conditional lubricant oil transport simulation and oil consumption prediction in internal combustion engines

Zhong

Tian

2023

Proceedings of the Institution of Mechanical Engineers, Part J:

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Reducing lubricant oil consumption (LOC) has long been an interest to engine manufacturers in an effort to reduce overall emissions from internal combustion (IC) engines. However, directly correlating engine operating conditions with LOC rates is a challenging task given its complex and multi-physics nature. Building on previous experimental observations and modeling efforts, a baseline hybrid model, which combines traditional physics-based numerical simulation with modern machine learning techniques, was developed. As the first step, the model is to compute the oil exiting the top ring gap with given oil supply rate and locations to the second land. Studies performed using the model reveal a strong dependency of LOC on engine speed, load as well as the relative locations of piston ring gaps. In particular, the close proximity of the oil source on second land to the top ring gap and the reverse gas flow at low load conditions can both induce high LOC. Piston ring gap rotations and the different oil supply mechanisms to the piston ring pack are also found to heavily influence the oil consumption behavior and oil film thickness distribution pattern. The present work is the first step to a more comprehensive model for predicting LOC for healthy systems of piston ring packs. The efficiency of the model made it possible to study the oil redistribution that takes many engine cycles to reach equilibrium and rotation of the ring gaps that could happen in reality at a time scale of minutes and even longer.

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Predictive Piston Cylinder Unit Simulation - Part I: Novel Findings on Cyclic Inter-Ring Pressure Measurements and Piston Ring Dynamic Simulation Validation

Cited by 5 publications

References 29 publications

Experimental Investigation of a Free-Form Honed Cylinder Liner for Heavy-Duty Engines

Experimental Investigation of a Free-Form Honed Cylinder Liner for Heavy-Duty Engines

An experimental investigation of low viscosity lubricants on three piece oil control rings cylinder liner friction

Hybrid digital twin for conditional lubricant oil transport simulation and oil consumption prediction in internal combustion engines

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