Transient plasto-elastohydrodynamic lubrication concerning surface features with application to split roller bearings

The use of roller bearings as crankshaft main bearings has shown potential in reducing the fuel consumption of internal combustion engines. An effective way to mount the roller bearing onto the crankshaft is to split the outer ring. However, this may lead to a severe out-of-roundness in the split region when the bearing is mounted, further implying increased noise, vibrations and contact stresses. In this work, a novel approach to study the plasto-elastohydrodynamic contact using commercial finite element software is developed. The modelling approach is based on the contact moving in space, allowing for the stress history based on the lubricant pressure to be studied in a straight-forward manner. The model is first utilised to study the influence of asperities on the lubricating conditions, indicating that stresses may exceed the yield strength of the material due to the transient effects taking place when the surface feature is over-rolled. Thereafter, the model is used to analyse the step in a mounted crankshaft roller bearing with the purpose of specifying a critical step height, which implies zero plasticity and thereby a reduced risk of accumulated damage in the vicinity of the step.

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Reactive computational fluid dynamics modelling of methane–hydrogen admixtures in internal combustion engines: Part I – RANS

International Journal of Engine Research ◽

10.1177/1468087420916380 ◽

2020 ◽

pp. 146808742091638

Author(s):

Jann Koch ◽

Christian Schürch ◽

Yuri M Wright ◽

Konstantinos Boulouchos

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Internal Combustion Engines ◽

Turbulent Flame ◽

Internal Combustion ◽

Flame Speed ◽

Combustion Engines ◽

Hydrogen Addition ◽

Dynamics Modelling ◽

Modelling Approach

The effects of hydrogen addition to internal combustion engines operated by natural gas/methane has been widely demonstrated experimentally in the literature. Already small hydrogen contents in the fuel show promising benefits with respect to increased engine efficiency, lower CO2 emissions, extended lean operating limits and a higher exhaust gas recirculation tolerance while maintaining the knock resistance of methane. In this article, the influence of hydrogen addition to methane on a spark ignited single cylinder engine is investigated. This article proposes a modelling approach to consider hydrogen addition within three-dimensional reactive computational fluid dynamics in order to establish a framework to gain further insights into the involved processes. Experiments have been performed on a single-cylinder spark-ignition engine situated at a test bed and cater as reference data for validating the proposed reactive computational fluid dynamics modelling approach based around the G-Equation combustion model. Within the course of the first part, crucial aspects relevant to the modelling of the mean engine cycle are highlighted. In this article, a simplified early combustion phase model which considers the transition towards a fully developed turbulent flame following ignition is introduced, along with a second submodel considering combined effects of the walls. The sensitivity of the combustion process towards the modelling approach is presented. The submodels were calibrated for a reference operating point, and a sweep in hydrogen content in the fuel as well as stoichiometric and lean operation has been considered. It is shown that the flame speed coefficient A appearing in the used turbulent flame speed closure, weighting the influence of the turbulent fluctuating speed [Formula: see text], has to be adjusted for different hydrogen contents. The introduced submodels allowed for significant improvement of the in-cylinder pressure and heat release rate evolution throughout all considered operating conditions.

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Laser Ignition in Internal Combustion Engines- a Novel Approach Based on Advanced Lasers

Advanced Solid-State Photonics (TOPS) ◽

10.1364/assp.2005.812 ◽

2005 ◽

Cited By ~ 1

Author(s):

Martin Weinrotter ◽

Herbert Kopecek ◽

Josef Graf ◽

Johann Klausner ◽

Günther Herdin ◽

...

Keyword(s):

Internal Combustion Engines ◽

Internal Combustion ◽

Laser Ignition ◽

Combustion Engines ◽

Novel Approach

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A Novel Approach to the Thermal Management of Internal Combustion Engines

Energy Procedia ◽

10.1016/j.egypro.2017.08.300 ◽

2017 ◽

Vol 126 ◽

pp. 883-890 ◽

Cited By ~ 3

Author(s):

Teresa Castiglione ◽

Sergio Bova ◽

Mario Belli

Keyword(s):

Thermal Management ◽

Internal Combustion Engines ◽

Internal Combustion ◽

Combustion Engines ◽

Novel Approach

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A Novel Approach to Model the Lubrication and Friction between the Twin-Land Oil Control Ring and Liner with Consideration of Micro Structure of the Liner Surface Finish in Internal Combustion Engines

10.4271/2008-01-1613 ◽

2008 ◽

Cited By ~ 11

Author(s):

Haijie Chen ◽

Yong Li ◽

Tian Tian

Keyword(s):

Surface Finish ◽

Internal Combustion Engines ◽

Internal Combustion ◽

Combustion Engines ◽

Micro Structure ◽

Novel Approach ◽

Liner Surface

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An integrated model for the performance of piston ring pack in internal combustion engines

Proceedings of the Institution of Mechanical Engineers Part K Journal of Multi-body Dynamics ◽

10.1177/1464419317736676 ◽

2017 ◽

Vol 232 (3) ◽

pp. 371-384 ◽

Cited By ~ 1

Author(s):

Kamel G Mahmoud ◽

Oliver Knaus ◽

Tigran Parikyan ◽

Guenter Offner ◽

Stjepan Sklepic

Keyword(s):

Internal Combustion Engines ◽

Piston Ring ◽

Three Dimensional ◽

Combustion Engines ◽

Two Dimensional ◽

Modelling Method ◽

Ring Dynamics ◽

Piston Ring Pack ◽

Ring Pack ◽

Modelling Approach

Piston rings are important components in internal combustion engines. Their primary function is to seal dynamically the gap between moving piston and cylinder liner surface in order to prevent the combustion gases from penetrating into the crankcase. The rings also control the oil leakage from the crankcase to the combustion chamber. The performance of the piston ring pack impacts the engine efficiency, durability and emissions. The recognition of the impact of the ring-pack performance on the engine design resulted in a sustained effort of research and development aimed at understanding the operation of the piston ring pack. Most of the published models developed in this field are two-dimensional assuming that the ring and liner are perfect circles for the purpose of modelling the axial and radial dynamics. Although this approach has proved to be useful, there exist a number of asymmetrical characteristics of the power cylinder system that can be crucial to the ring-pack performance and therefore it is considered to be appropriate. In this work, an integrated methodology that handles the complex ring-pack mechanism is presented. The physics of the ring-pack mechanism covers the three-dimensional piston ring dynamics of asymmetric engine cylinder due to bore distortion, the mixed lubrication at ring running face as well as the ring flanks and the interring gas dynamics. The modelling method is verified in two steps. In the first step, the dynamic behaviour of the three-dimensional ring model is verified against a commercial finite element software by comparing the eigenmodes up to a frequency of about 1 kHz. In the second step, the ring-pack modelling approach using three-dimensional ring models is also verified against a commercial ring dynamics program, which is based on the two-dimensional modelling. It is shown that the three-dimensional ring dynamics modelling method has advantages over the two-dimensional modelling approach as it facilitates studying the influence of the non-uniform twist along its circumference (ring winding), the effect of bore distortion on blow-by, ring friction, friction power losses and wear.

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Basic Principles in the Design of Cathode Ray Oscillograph Engine Indicators

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1940_143_015_02 ◽

1940 ◽

Vol 143 (1) ◽

pp. 48-56 ◽

Cited By ~ 2

Author(s):

F. D. Smith

Keyword(s):

Direct Current ◽

High Frequency ◽

Internal Combustion Engines ◽

Alternating Current ◽

Combustion Engines ◽

Transient Effects ◽

Mechanical Pressure ◽

Basic Principles ◽

Electrical Effect ◽

Suitable Combination

Increases in the speed and rating of internal combustion engines have necessitated the replacement of conventional engine indicators by the recently evolved cathode ray oscillograph engine indicator. The devices for converting mechanical pressure into an electrical effect fall into three classes according to whether (1) an electrostatic, (2) a resistance, or (3) an electromagnetic effect is used. Only the first and last classes have been found practicable, the first for rapidly varying and transient effects, and the last for slower phenomena. The members of each class can be used with one of three types of electrical energizing circuits: (1) self-excitation, (2) direct-current excitation, or (3) alternating-current excitation. Success in dealing with a particular problem depends upon the choice of a suitable combination of the device sensitive to pressure, and the electrical energizing circuit. The three most useful combinations are the piezo-electric crystal, and the moving iron, or magnetophone, with either direct-current, or high-frequency alternating-current excitation. Magnetostriction and the condenser microphone, both with either direct- or alternating-current excitation, will prove useful when developed further. The essential features of design for the study of the most difficult problems are now understood. The present form of these engine indicators is useful, but there is need for greater accuracy and reliability.

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