Deformation Of Cylinder Liner Research Articles

Cylinder liner deformation characteristics based on fourier transform and impact on ring pack sealing and friction power

Cylinder liner deformation characteristics based on fourier transform and impact on ring pack sealing and friction power

Study on the frictional properties of the top ring-liner conjunction for different-viscosity lubricant

In modern internal combustion engines, the lubricant viscosity affects greatly the friction power loss. To obtain maximum fuel economy of the engines, the lubricants with different viscosities are considered to evaluate the friction properties of the compression ring-cylinder liner conjunction in the engines in this study. To conduct the evaluation, an improved mixed lubrication model is developed with considerations of the cylinder liner deformation, the lubricant thermal effect & transportation, and the change of lubrication condition from full flooded to starve. On this basis, the influence of different viscosity lubricants on the minimum oil film thickness, friction, power loss, FMEP, and wear load are investigated. The numerical result indicates that the low viscosity lubricant is more beneficial to facilitate the change of lubrication condition from starve to fully flooded. Furthermore, the low viscosity lubricant will result in large wear load on the compression ring surface while reducing the friction power loss.

Simulation on the effect of cylinder liner and piston ring surface roughness on friction performance

Considering the surface roughness of piston ring and cylinder liner and deformation of cylinder liner, the friction dynamics calculation model of cylinder liner-piston ring friction pair was established. The effects of top ring, other piston rings and cylinder liner surface roughness on friction performance were analyzed by grouping comparison and Box-Behnken response surface methodology. The calculation results show that when the surface roughness of the piston ring increases, the friction of the asperity increases slightly, the friction of the fluid decreases, and the total friction loss decreases. When the surface roughness of the cylinder liner increases, the friction of the asperity decreases slightly, the friction of the fluid increases, and the total friction loss increases.

Study on Deformation Characteristics of Diesel Engine Cylinder Liner under Different Influencing Factors

To study the influence of different influencing factors on the cylinder liner deformation characteristics, the finite element method was used to analyze the cylinder liner deformation under the pre-tightening condition of the diesel engine block-cylinder head assembly. Fourier spectrum, coaxiality, and main thrust surface inner diameter change were selected as deformation evaluation indicators to comprehensively evaluate cylinder liner deformation. The influence laws of several typical load parameters, structural parameters, and material parameters on cylinder liner deformation have been studied and sensitivity has been used to characterize the degree of influence of influencing factors on each deformation evaluation indicator. The research results can guide the evaluation and control of cylinder liner deformation under the pre-tightening condition.

Analysis of out-of-round deformation of a dry cylinder liner of a non-road high-pressure common-rail diesel engine based on multi-field coupling

The deformation of cylinder liner directly affects the sealing performance of the friction components in internal combustion engines, resulting in high oil consumption, engine power loss, and high-particulate matter emissions. Previous research works focused more on deformation of the wet vehicular cylinder liners, however, the effects of different loads on the dry liner deformation is not clear yet. A non-road high-pressure common-rail diesel engine was selected as the research object, and a coupled model of the engine was developed based on fluid–solid coupled heat transfer theory. After the accuracy of the model was verified by temperature measurement of the cylinder head and cylinder liner, deformation of the dry cylinder liner was studied. The results show that the axial and radial deformations of the cylinder liner are not uniform under the bolt preload condition. Large deformation occurs at the first liner and fourth liner, with the maximum deformation occurring at the top of fourth liner for 10.14 μm. Under the condition of thermal load, the temperature of cylinder liner exhibits a distribution of three-segments from the top to bottom. The liner deformation is not uniform, and the maximum deformation occurs at the top of the fourth liner for 304 μm. The radial deformations of all four cylinder liners present a symmetrical structure of a “heart” shape with respect to the centerline of the second and third cylinders. The axial deformation of each liner exhibits a “barrel” shape which is convex in the middle and narrow at the two ends.

Cylinder liner deformation orders and efficiency of a piston ring-pack

One of the several losses of a combustion chamber is the gas leakage toward the crankcase due to imperfect sealing of the rings. It is commonly known as blow by and it affects efficiency and emissions. The paper initially describes a bibliographic review of the phenomenon, together with the equations of the system. A typical piston ring pack for internal combustion engine is proposed to be analysed and solved using ©Ricardo RINGPAK Solver. A specific issue such as Bore distortion orders were used to investigate the sealing capacity of the ring-pack in terms of ring dynamics, inter-ring pressures and mass flows. Bore distortion orders and their magnitude showed to affect the ring pack behavior. Order zero distortion resulted to be the most important order due to the highest amount of gas lost in the crankcase, while orders three and four resulted to generate high blow-by values, even if their magnitude of distortion is lower in comparison to other orders.

Evaluation on the tribological performance of ring/liner system under cylinder deactivation with consideration of cylinder liner deformation and oil supply.

In gasoline engines, CDA (cylinder deactivation) affects greatly the tribological performance of ring/liner system while reducing the emissions and improving the fuel economy. The analyses on the tribological performance of ring/liner system under the CDA mainly focus on the ideal circular cylinder liner and fixed fully flooded lubrication condition. In this study, a numerical investigation on the tribological performance of a compression ring-cylinder liner system is presented under the CDA with consideration of the cylinder liner deformation and the transition between the fully flooded and starved lubrication conditions. A mixed lubrication model coupled with oil transport model and JFO (Jacobson-Floberg-Olsson) conservative cavitation algorithm is proposed to evaluate the frictional properties. Based on the model, the tribological performance is investigated under the standard operation condition and the CDA. Meanwhile, the influence of cylinder liner deformation and oil supply on the tribological performance is also evaluated. Results show that the tribological performance of the compression ring-cylinder liner system is greatly changed when the CDA is adopted. In particular, under the CDA, the overall power loss and FMEP (friction mean effective pressure) value are increased about 27.29% and 53.51%. The study also demonstrates the necessity to consider the cylinder liner deformation and oil supply in the simulation of compression ring-cylinder liner system under the CDA.

Numerical Study on the Tribological Performance of Ring/Liner System With Consideration of Oil Transport

The tribological performance of a compression ring-cylinder liner system (CRCL) is numerically studied. A thermal-mixed lubrication model is developed for the lubrication analysis of the CRCL with consideration of the cylinder liner deformation. An oil transport model coupled with a mass conservation cavitation algorithm is employed to predict the oil consumption and the transition between the fully flooded lubrication condition and starved lubrication condition. On this basis, the effects of the oil supply and cylinder liner deformation on the frictional characteristics are investigated under cold and warm engine conditions. The results show that the cylinder liner deformation and oil supply have great influence on the tribological performance of the CRCL. Better tribological performance and lower oil consumption can be obtained by reasonably controlling the oil supply.

Numerical analysis of the effects of compression ring wear and cylinder liner deformation on the thermal mixed lubrication performance of ring-liner system

The lubrication performance of roughness compression ring-cylinder liner system (CRCL) with axial-asymmetric new/worn compression ring and out-of-round cylinder liner is studied in this paper. By considering the oil film thermal effect, cavitation phenomenon, and surface roughness, the energy equations, mass conservation Jacoboson-Floberg-Olsson (JFO) cavitation algorithm, generalized average Reynolds equation, and Greenwood-Tripp asperity contact model are employed to investigate the frictional behaviors of CRCL. The oil film thickness, friction forces, wear, and power loss of CRCL are investigated at various wear stages of compression ring. The effects of the magnitude of cylinder liner deformation on the frictional characteristics of CRCL are also analyzed with consideration of compression ring conformability. Numerical results show that the deformation of cylinder liner and the wear of compression ring have a significant influence on the lubrication performance. It also suggests that the oil film thermal effect should be considered in the numerical analysis to provide an accurate prediction on the frictional behaviors of CRCL.

An Improved Lubrication Model between Piston Rings and Cylinder Liners with Consideration of Liner Dynamic Deformations

The friction pair of piston rings and cylinder liner is one of the most important friction couplings in an internal combustion engine. It influences engine efficiency and service life. Under the excitation of piston slaps, the dynamic deformation of cylinder liner is close to the surface roughness magnitudes, which can affect the friction and lubrication performance between the piston rings and cylinder assemblies. To investigate the potential influences of structural deformations to tribological behaviours of cylinder assemblies, the dynamic deformation of the inner surface due to pistons slaps is obtained by dynamic simulations, and then coupled into an improved lubrication model. Different from the traditional lubrication model which takes the pressure stress factor and shear stress factor to be constant, the model proposed in this paper calculated these factors in real time using numerical integration to achieve a more realistic simulation. Based on the improved piston rings and cylinder liner lubrication model, the minimum oil film thickness and friction force curves are obtained for an entire work cycle. It shows that the friction force obtained from the improved model manifests clear oscillations in each stoke, which is different from the smoothed profiles predicted traditionally. Moreover, the average amplitude of the friction forces also shows clear reduction.

Blow-by and tribological performance of piston ring pack during cold start and warm idle operations

To reduce the fuel consumption of internal combustion engines, more attention has been paid to the tribological performance of the piston ring pack during the cold start and idle operations. In this research, a numerical model considering the cylinder liner deformation and the piston ring conformability is developed to predict the blow-by, lubrication, friction and wear of the piston ring pack under different operating conditions. The gas flow rate, inter-ring gas pressures, minimum oil film thickness, frictional force and wear load during cold start are calculated and compared with those during warm idle operating conditions. The results show that cylinder liner deformation and piston ring conformability together obviously affect blow-by and other tribological performance. Meanwhile, it is found that friction loss is larger during cold start than during warm idle operating conditions. However, the wear process is more severe during warm idle operation than during cold start. From this research, the blow-by and tribological performance of the piston ring pack during cold start and warm idle operations are understood more deeply.

Tribological performance evaluation and sensitivity analysis of piston ring lubricating film with deformed cylinder liner

The interface between piston ring and cylinder liner is lubricated with an oil film to improve wear resistance and operating life of the engine. The high combustion pressure, variable loadings, manufacturing errors, and thermal distortions in the engine cylinder deform the cylinder liner, thus making a significant effect on the lubricant performance. To investigate the effects of cylinder liner deformation on the piston ring lubrication, a 2D model of elastohydrodynamic lubrication under fully flooded conditions was considered. Various elliptically deformed profiles of the cylinder liner were tested to evaluate conformability, lubricating film thickness, friction, power loss, and lubrication flow rate for a complete four-stroke engine cycle. Comparative analysis of the simulation results was conducted to evaluate the dependency of engine performance on deformed bore shape. Results showed that the lubricating film thickness and engine performance parameters strongly depend on the cylinder liner shape and the degree of distortion.

Impact of the Piston Secondary Motion on its Slap Force

A theoretical model is developed for the analysis of piston secondary motion. Based on this model, the slap force of a specific L6 diesel engine was compared when considering different boundary conditions, such as lubricating oil on cylinder liner, surface roughness, deformation of cylinder liner and piston skirt. It is concluded that it is necessary to consider the secondary motion of piston in the analysis of the inner excitation for an internal combustion engine. A more comprehensive consideration of the boundary condition (i.e., more close to the actual condition) will lead to a smaller maximum slap force, and among all boundary conditions considered in this paper, the structural deformation of the piston skirt and cylinder liner is the most influential factor. The theoretical model developed and findings obtained in this study will benefit the future analysis and design of advanced internal combustion engine structures.

The Simulation Research on Assembly Deformation of Internal Combustion Engine Cylinder Liner

For the commonly used wet cylinder liner assembly characteristics and structure of water-cooled internal combustion engine, the influencing factors of wet cylinder liner deformation in the assembly conditions are calculated and analyzed using finite element method. Mainly from the matching stiffness of block-cylinder liner-gasket-cylinder head assembly, the local stiffness of the cylinder head, cylinder head bolt preload and the structure form of cylinder liner, get the influence laws of the various factors on the cylinder liner radial deformation and its each order Fourier series deformation, which provides guidance direction to control the cylinder liner deformation under assembly loading.

The Research on the Structure Parameters to Deformation of the 150 Diesel Engine Cylinder under Thermo-Mechanical Coupling

Finite element method with experimental data was used to calculate and analysis the temperature field and machine assembly of a 150 engine cylinder liner. Using a series of evaluation criteria such as maximum, minimum radius, light leakage rate to analyze the influence of the main structural parameters on the cylinder liner deformation in the coupling effect of Thermal stress and mechanical stress. Comparative results show that: increasing the wall thickness of cylinder liner can reduce the radial deformation of the cylinder liner effectively, the diameter of the cylinder liner shroud has little effect on the cylinder liner radial deformation, but it can reduce the local stress concentration of the cylinder liner, cylinder shroud thickness increases can lead to the radial deformation of the cylinder liner increasing.

The Analysis of the Temperature Field and Deformation of Cylinder Liner Base on Finite Element Method and Experiment

The distortion of the cylinder liners of internal combustion engines has a significant affect on engine operation. It can affect the oil consumption, the blow-by, the wear behavior and, due to friction, the fuel consumption. In order to achieve future requirements regarding exhaust emissions and fuel consumption, the development of low distortion engine blocks will play a significant role. Finite element method with experimental data were used to calculate and analysis the temperature field and machine assembly of a 150 engine cylinder liner in this paper. It can provide a theoretical basis for the controlling of the cylinder liner deformation.

Study on Thermal Stresses of Cylinder Liner’s Fabrication Using FEM Analysis

In the process of casing casting, great temperature gradient leads to contraction deformation of cylinder liner, which influences the quality of products. The thermal stresses caused by temperature gradient were analyzed by finite element method. The numerical results show that high equivalent Von Mises stress(242MPa) occurs in the surface zone of the cylinder liner as Cooling down to room temperature within pipe die ,also there is plastic deformation in the internal and external surface zone. Reducing the cooling speed, decreasing the temperature gradient and aging can reduce the influence of thermal stresses.