Elastohydrodynamic Lubrication and Asperity Contact Simulation of Engine Main Bearing with Flexible Rotating Crankshaft and Flexible Engine Block

2009 ◽  
pp. 967-972 ◽  
Author(s):  
Liang Chen ◽  
Xigeng Song ◽  
Dongxin Xue ◽  
Zhangjie Ming
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Engine Block ◽  
Asperity Contact ◽  
Main Bearing

Transient tribodynamic analysis of crankshaft-main bearing system during engines starting up

2017 ◽  
Vol 232 (5) ◽  
pp. 535-549 ◽  
Author(s):  
Ruichao Liu ◽  
Xianghui Meng ◽  
Peng Li
Keyword(s):  
Internal Combustion Engines ◽  
Surface Deformation ◽  
Elastohydrodynamic Lubrication ◽  
Viscous Friction ◽  
Friction Loss ◽  
Asperity Contact ◽  
Main Bearing ◽  
Start Up ◽  
Run Up ◽  
Bearing System

The starting-up process of internal combustion engines presents a great challenge to the tribodynamic performance of the crankshaft-main bearing system. In this study, a transient mixed elastohydrodynamic lubrication model is presented to investigate the transient process. In the model, the average Reynolds equation is adopted with considering the influences of surface deformation and starting temperature. Then the oil film and friction loss of the system and the journal center trajectory during engines starting up are analyzed. The results at different starting temperatures show that the asperity contact under the hot start-up condition is more serious. However, during the engine run-up and transition to idling phases, more viscous friction loss is generated under the cold start-up condition.

Lubrication Simulation of Main Bearing about a Marine Diesel Engine Based on Multi-Body Dynamics and Elastohydrodynamic

2011 ◽  
Vol 347-353 ◽  
pp. 2679-2683
Author(s):  
Li Dui Wei ◽  
Shu Lin Duan ◽  
Qi Li Wu ◽  
Ji Wu ◽  
Wei Guo
Keyword(s):  
Diesel Engine ◽  
Load Condition ◽  
Engine Block ◽  
Asperity Contact ◽  
The Finite Element Method ◽  
Main Bearing ◽  
Working Cycle ◽  
Body Dynamics ◽  
Marine Diesel ◽  
Multi Body

The purpose of this paper is to find a method to study the lubrication character of the main bearings and load condition of the crankshaft about the marine two-stroke diesel engine. Based on the finite element method, multi-body dynamics, elastohydrodynamic and Green-Tripp theory about contact, the simulation of coupling between the elastic crankshaft and engine block is carried out. The load of main bearings, the minimum of oil film thick, orbital path of journal, average of asperity contact pressure are explored. The results indicate that the lubrication is good except No.2 main bearing. Parts of main bearings appear three peaks in a working cycle, which shows that above theory and elastic crankshaft and engine block is obligatory to simulate the lubrication and load condition accurately.

Numerical Modeling of Mixed Lubrication and Flash Temperature in EHL Elliptical Contacts

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Neelesh Deolalikar ◽  
Farshid Sadeghi ◽  
Sean Marble
Keyword(s):  
Surface Deformation ◽  
Elastohydrodynamic Lubrication ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Lubrication Regime ◽  
Predicting Performance ◽  
Pure Rolling ◽  
Rolling Element ◽  
Contact Pressures ◽  
Film Lubrication

Highly loaded ball and rolling element bearings are often required to operate in the mixed elastohydrodynamic lubrication regime in which surface asperity contact occurs simultaneously during the lubrication process. Predicting performance (i.e., pressure, temperature) of components operating in this regime is important as the high asperity contact pressures can significantly reduce the fatigue life of the interacting components. In this study, a deterministic mixed lubrication model was developed to determine the pressure and temperature of mixed lubricated circular and elliptic contacts for measured and simulated surfaces operating under pure rolling and rolling/sliding condition. In this model, we simultaneously solve for lubricant and asperity contact pressures. The model allows investigation of the condition and transition from boundary to full-film lubrication. The variation of contact area and load ratios is examined for various velocities and slide-to-roll ratios. The mixed lubricated model is also used to predict the transient flash temperatures occurring in contacts due to asperity contact interactions and friction. In order to significantly reduce the computational efforts associated with surface deformation and temperature calculation, the fast Fourier transform algorithm is implemented.

scholarly journals Stress analysis of the cylinder block of a small compression ignition engine

2019 ◽  
Vol 179 (4) ◽  
pp. 259-263
Author(s):  
Jerzy WAWRZYCZEK ◽  
Tomasz KNEFEL
Keyword(s):  
Stress Analysis ◽  
Cylinder Head ◽  
Engine Block ◽  
Cylinder Block ◽  
Small Displacement ◽  
Compression Ignition ◽  
Main Bearing ◽  
Compression Ignition Engine ◽  
Combustion Pressure

The work contains calculations to determine the deformation and stress in the block of a currently produced small displacement compression ignition engine. It is also an attempt to introduce some modifications to reduce the mass of the calculated component. In the first step, based on measurements, the model of the engine block was developed. The Autodesk Inventor 2016 software was used. Two additional components were also designed to provide the block closure: a simplified cylinder head and an integrated main bearing support. All elements were imported to the Siemens NX 12 program. The calculations were carried out for different cylinders and different values of the combustion pressure. An attempt was made to introduce some modifications to reduce the weight of the calculated element.

scholarly journals Decision Support System For Determining Power Loss And Refurbishability Of Failed Automotive Petrol Engine Block And Crankshaft

2021 ◽  
Author(s):  
BASIL OLUFEMI AKINNULI ◽  
OLADELE AWOPETU ◽  
OLUWASEUN OLUWAGBEMIGA OJO
Keyword(s):  
Decision Support ◽  
Power Loss ◽  
Computer Software ◽  
Engine Block ◽  
Measuring Instruments ◽  
Main Bearing ◽  
Test Engine ◽  
Cause Of Failure ◽  
Improved Performance ◽  
The Cost

Abstract The crankshaft and engine block of automobile wear or fail after certain years of usage. The cause of failure is a contributing factor to the power loss of the engine. Power loss reduces the performance of the vehicle. Due to the economic situation in Nigeria, the cost of buying new engines is usually high and some used engines have problems that are latent. Pre-test engine analysis was carried out and torque of each selected engine was measured with a dynamometer to know the speed of the worn engine. Disassembly of four (4) cylinder engines namely; Toyota, Nissan, Mitsubishi, and Mazda were carried out and the affected failed parts, namely; main bearing, crankpin journal, and bore cylinder diameter were determined and the level of their wear as well as power losses ascertained using measuring instruments. For easy computation and analysis, a computer software using C-sharp programming language was developed to determine the power loss and predicting machining level of refurbish-ability and tested for performance evaluation. The model and its developed software are decision support tools for any automotive industry where maintenance and management of engines for improved performance and efficiency of operation is the focus.

scholarly journals Effects of bushing profiles on the elastohydrodynamic lubrication performance of the journal bearing under steady operating conditions

2019 ◽  
Vol 20 (2) ◽  
pp. 207 ◽  
Author(s):  
Chongpei Liu ◽  
Bin Zhao ◽  
Wanyou Li ◽  
Xiqun Lu
Keyword(s):  
Journal Bearing ◽  
Elastohydrodynamic Lubrication ◽  
Operating Conditions ◽  
Asperity Contact ◽  
Parabolic Profile ◽  
Leakage Flow Rate ◽  
Lubrication Performance ◽  
Load Carrying ◽  
Edge Wear ◽  
Flow Rate Change

The bushing profiles have important effects on the performance of journal bearing. In this article, the effects of plain profile, double conical profile, and double parabolic profile on the elastohydrodynamic lubrication of the journal bearing under steady operating conditions are investigated. The journal misalignment and asperity contact between journal and bushing surface are considered, while the modification of the bushing profiles due to running-in is neglected. Finite element method is used for the elastic deformation of bushing surface, while the numerical solution is established by using finite difference method and overrelaxation iterative method. The numerical results reveal that the double parabolic profile with appropriate size can significantly increase the minimum film thickness and reduce the asperity contact pressure and friction, while the maximum film pressure, load-carrying capacity, and leakage flow rate change slightly under steady operating conditions. This study may help to reduce the edge wear and prolong the service life of the journal bearing.

A numerical method to investigate the mixed lubrication performances of journal-thrust coupled bearings

2019 ◽  
Vol 71 (9) ◽  
pp. 1099-1107
Author(s):  
Guo Xiang Guo Xiang ◽  
Yanfeng Han ◽  
Renxiang Chen ◽  
Jiaxu Wang Jiaxu Wang ◽  
Ni Xiaokang
Keyword(s):  
Thrust Bearing ◽  
Load Capacity ◽  
Elastohydrodynamic Lubrication ◽  
Hydrodynamic Pressure ◽  
Mixed Lubrication ◽  
Hydrodynamic Effect ◽  
Asperity Contact ◽  
Content Type ◽  
Lubrication Regime ◽  
Coupled Effect

Purpose This paper aims to present a numerical model to investigate the mixed lubrication performances of journal-thrust coupled bearings (or coupled bearings). Design/methodology/approach The coupled hydrodynamic effect (or coupled effect) between the journal and the thrust bearing is considered by ensuring the continuity of the hydrodynamic pressure and the flow field at the common boundary. The mixed lubrication performances of the coupled bearing are comparatively studied for the cases of considering and not considering coupled effect. Findings The simulated results show that the hydrodynamic pressure distributions for both the journal and thrust bearing are modified due to the coupled effect. The decreased load capacity of the journal bearing and the increased load capacity of the thrust bearing can be observed when the coupled effect is considered. And the coupled effect can facilitate in reducing the asperity contact load for both the journal and thrust bearing. Additionally, the interaction between the mixed lubrication behaviors, especially for the friction coefficient, of the journal and the thrust bearing is significant in the elastohydrodynamic lubrication regime, while it becomes weak in the mixed lubrication regime. Originality/value The developed model can reveal the mutual effects of the mixed lubrication behavior between the journal and the thrust bearing.

An EHD-mixed lubrication analysis of main bearings for diesel engine based on coupling between flexible whole engine block and crankshaft

2015 ◽  
Vol 67 (2) ◽  
pp. 150-158 ◽  
Author(s):  
Lidui Wei ◽  
Haijun Wei ◽  
Shulin Duan ◽  
Yu Zhang
Keyword(s):  
Diesel Engine ◽  
Flow Model ◽  
Mixed Lubrication ◽  
Engine Block ◽  
Contact Theory ◽  
Asperity Contact ◽  
Block Model ◽  
Content Type ◽  
Oil Film ◽  
Average Flow Model

Purpose – The purpose of this paper is to develop a good calculation model to accurately predict the lubrication characteristic of main bearings of diesel engine and improve the service life. Design/methodology/approach – Based on the coupling of the whole flexible engine block and the flexible crankshaft reduced by the Component Mode Synthesis (CMS) method, considering mass-conserving boundary conditions, the average flow model equation and Greenwood/Tripp asperity contact theory, an elastohydrodynamic (EHD)-mixed lubrication model of the main bearings for the diesel engine is developed and researched with the finite volume method and the finite element method. Findings – Obviously, the mixed lubrication of bearings is normal, while full hydrodynamic lubrication is transient. The results show that under the whole flexible block model, maximum oil film pressure, maximum asperity contact pressure and radial shell deformation decrease, while minimum oil film thickness increases. Oil flow over edge decreases, and so does friction loss. Therefore, coordination deformation ability of whole engine block is favorable to mean load. In the whole block model, friction contact happens on both upper shell and lower shell positions. In addition, average oil film fill ratio at the key position becomes smaller in the whole engine block model, and consequently increases the chances of cavitations erosion more. So, wearing resistance of both upper and lower shells and anti-cavitations erosion ability must be enhanced simultaneously. Originality/value – Based on the coupling of the whole flexible engine block and the flexible crankshaft reduced by the CMS method, considering mass-conserving boundary conditions, the average flow model equation and Greenwood/Tripp asperity contact theory, an EHD-mixed lubrication model of the main bearings for the diesel engine is built, which can predict the lubrication of journal bearings more accurately.

3-D Numerical Simulation and Experiment Study on the Wear of Piston Ring-Cylinder Liner

2010 ◽  
Vol 139-141 ◽  
pp. 1036-1039 ◽  
Author(s):  
Jian Ping Zhang ◽  
Yan Kun Jiang ◽  
Xin Liu ◽  
Zhe Lin Dong
Keyword(s):  
Diesel Engine ◽  
Piston Ring ◽  
Elastohydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Effect Of Temperature ◽  
Wear Loss ◽  
Asperity Contact ◽  
Warm Start ◽  
Deformation Equation ◽  
Marine Diesel

Aiming at a large marine diesel engine, a mathematical model for the 3-D elastohydrodynamic lubrication analysis of piston ring-cylinder liner was presented. The average Reynolds equation and asperity contact approach were combined with the elastic deformation equation. The asymmetry in the circumferential direction, gas blowby and the effect of temperature and pressure on the oil density and viscosity were considered. The 3-D wear simulation of piston ring-cylinder liner was performed when the diesel engine was operated under warm start and cold start conditions, respectively. The 3-D distribution rules show that the first gas ring has the biggest wear loss, and the maximum wear loss of cylinder liner occurs in the vicinity of TDCF. Finally, the results matched well with the wear measurements, and it indicates the present method is effective and can help engineers to improve the tribological performance of the diesel engine.

An Elastohydrodynamic Coupling of a Rotating Crankshaft and a Flexible Engine Block

2004 ◽  
Vol 126 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Omidreza Ebrat ◽  
Zissimos P. Mourelatos ◽  
Kexin Hu ◽  
Nickolas Vlahopoulos ◽  
Kumar Vaidyanathan
Keyword(s):  
Finite Difference ◽  
Component Mode Synthesis ◽  
Engine Block ◽  
Main Bearing ◽  
Equilibrium Conditions ◽  
Structural Dynamic ◽  
Mapping Algorithm ◽  
Computational Capability ◽  
Body Dynamics ◽  
Flexible Body Dynamics

A comprehensive formulation is presented for the dynamics of a rotating flexible crankshaft coupled with the dynamics of an engine block through a finite difference elastohydrodynamic main bearing lubrication algorithm. The coupling is based on detailed equilibrium conditions at the bearings. The component mode synthesis is employed for modeling the crankshaft and block dynamic behavior. A specialized algorithm for coupling the rigid and flexible body dynamics of the crankshaft within the framework of the component mode synthesis has been developed. A finite difference lubrication algorithm is used for computing the oil film elastohydrodynamic characteristics. A computationally accurate and efficient mapping algorithm has been developed for transferring information between a high-density computational grid for the elastohydrodynamic bearing solver and a low-density structural grid utilized in computing the crankshaft and block structural dynamic response. The new computational capability is used to compute the vibratory response of an automotive V6 engine due to combustion and inertia loading.

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