Engine Liner Research Articles

ЭКСПЛУАТАЦИОННЫЕ ИСПЫТАНИЯ НАНОРАЗМЕРНОЙ ДОБАВКИ «КЛАСТЕР-В» К МОТОРНОМУ МАСЛУ ДИЗЕЛЯ КАМАЗ-740

At operation of KAMAZ motor vehicles a significant number of failures (40–55 %) are attributed to engine, among the elements of which a cylinder and piston group often breaks down. One of the effective ways to increase the wear resistance of rubbing parts of the engine is the modification of lubricating medium by special abovebase additives, among which nanoscale powders are widely distributed. The paper is devoted to investigation of influence of the «Klaster-V» nanoadditive that is developed for motor oil in order to increase life of a «piston ring — cylinder liner» interface of KAMAZ motor vehicles. As a parameter of technical condition of the interface the authors have assumed a value of a gap between a piston ring and a cylinder liner of an internal combustion engine. Results of operational tests show that the forecasting residual life of the «piston ring — cylinder liner» interface of diesel engines tested on oil with «Klaster-V» additive have increased by 2.15 times on average in comparison with the residual life of diesel engines operated on Lukoil 15W40 motor oil.

Wear assessment model for cylinder liner of internal combustion engine under fuzzy uncertainty

The wear of the piston ring-cylinder system is inevitable in the operation of the internal combustion engines (ICEs). If wear exceeds the maximum, the piston ring-cylinder system will be failure. A novel wear assessment model is proposed based on the support vector regression, and the fuzzy uncertainty is modeled to describe the random behavior under small sample. To verify the proposed model, the sample data of cylinder liner wear is applied. For best results, the particle swarm optimization (PSO) algorithm is used to optimize the model parameters. A back propagation neural network (BPNN) is employed to verify the effectiveness of the proposed model. The results show that the novel support vector regression has better prediction accuracy than other methods for cylinder wear in this paper, the proposed model can evaluate the cylinder liner wear of the ICEs effectively. The work provides a technical support for evaluating the service performance of the piston ring-cylinder liner and a reference for regular maintenance of the ships.

Determination of empirical correlation between OD and ID of liner of a multi cylinder diesel engine under mechanically distorted condition

For present work, the distortions in the liner due to mechanical torque application are considered and an empirical correlation between its inner diameter and outer diameter had been determined. This empirical correlation can be utilized eventually to estimate the mechanical bore distortion after actually running of engine. For estimation of total distortion i.e; mechanical as well as thermal distortion is required. As it is not possible to measure mechanical distortion of an engine after running, there as to be provision of estimation of same.As after assembly,it can not be measured experimentally,a suitable empirical correlation between inner diameter and outer diameter of liner under mechanically distorted condition, mechanical distortion, is developed and mechanical distortion is found out. After running the engine actually, and by measuring total distortion after disassemblying the liner ,the thermal distortion can be found subtracting mechanical distortion .

Tribological performance of nanolubricants dispersed with graphene oxide and detonation nanodiamond

Different compositions of graphene oxide (GO) and detonation nanodiamond (DND) nanoparticles with API CH-4 engine oil were tested on a reciprocating wear tester at high contact pressure. Significant reductions in friction and wear were observed. Wear surfaces were characterized by a 3D profiler, scanning electron microscopy and energy-dispersive X-ray spectroscopy to determine the surface topography, film build-up composition, mechanism of nanoadditive-assisted friction reduction and wear reduction characteristics. The wear tests indicated that the original engine liner segments containing surface texture with oil retention potential significantly lose their micropeaks and valleys during the test. Even though the surface texture got disturbed, the presence of nanoadditives in the lubricant led to a reduction in the coefficient of friction. Considerable reduction in the roughness level of the wear track associated with the use of a nanolubricant was also explored through the 3D profiler analysis. The surface roughness of the wear track produced while using a nanolubricant with 0.5 mg/l of detonation nanodiamond nanoparticles was 66% lower than the roughness of the wear track obtained with the base oil. The nanolubricant suspended with 1 mg/l detonation nanodiamond nanoparticles achieved a lower coefficient of friction earlier and a combination of detonation nanodiamond and GO at 0.5 mg/l concentration achieved the lowest coefficient of friction and wear at the end of the test duration.

Recommendations for selecting the characteristics of diamond bars when honing cylinder liners of internal combustion engines

The characteristics of diamond bars when honing engine cylinder liners are analyzed and general recommendations are given for their selection and processing modes.

Tribological performance of engine oil with graphene oxide nano additives on cylinder liner honing surface at high contact pressure

Improving the friction and wear characteristics of lubricants employing dispersed nanoparticles is a major area of research. This paper focuses on the wear and friction analysis of a plateau honed cylinder liner surface when lubricated with Graphene oxide nanoparticles dispersed in SAE 15 W40 API CH4 diesel engine oil. Experiments are carried out on a reciprocating tribometer. The friction coefficient and wear rate are used to quantify the tribological characteristics of lubricant added with nano-particles. On contrary to the past observations on polished surfaces, experiments conducted using honed engine liner and engine oils with nanoparticles have shown improvement only on the wear characteristics. It is noted that in case of a honed engine liner surface under high contact pressure lubricated with oil dispersed with 0.5 mg/l of Graphene oxide, the anti-wear characteristics improve by 37% whereas the coefficient of friction has only marginal improvement.

MODELING THE HEAT CONDITION OF A CYLINDER HOUSING OF A VEHICLE DIESEL

A characteristic feature of the cylinder liners of modern automotive and other types of internal combustion engines, which is confirmed by numerous engine tests, is a significant temperature difference along the height of the working surface - mirrors. Depending on the level of engine boost, temperatures can vary from 250-300℃ in the upper part of the liner, near the combustion chamber, to 80-90 ℃ in the lower part, cooled by a liquid cooler (water or antifreeze). From the point of view of ensuring optimal friction conditions, which are largely determined and depend on the viscosity of the engine oil at a given working temperature of the liner mirror, such temperatures for both the upper and lower parts of the liner are not optimal. The deterioration of friction conditions leads to an increase in mechanical losses, a decrease in the effective performance of the engine as a whole. As shown by the analysis of literature, the improvement of effective indicators, the reduction of mechanical losses in the cylinder-piston group is facilitated by measures to equalize the temperature of the liner in the working area of the compression rings and to bring temperatures to the level of 160–170 ℃. In the presented calculation study, which can be considered as an intermediate stage of refining the design of the cylinder liner in order to optimize the temperature profile of the working surface, the influence of the area of the cooled outer liner surface is considered. An analysis is made of a variant of a serial diesel engine liner 4CHN12 / 14 made of cast iron SCH21-40, and an experimental version, provided that it is made of aluminum alloy AL19 with a corundum working surface. As shown by previous computational studies, the constructive options for a cylindrical sleeve with minor changes to the basic version, which preserve the basic geometric dimensions of the part, in particular the distance between the upper and lower seat faces, do not solve the task of optimizing the temperature profile of the sleeve as for cast-iron sleeves, and liners made of aluminum alloy. The study analyzes the options that provide for more significant changes both in the design of the liner itself and in the design of the cylinder block, namely in the placement of the liner seal belts. For computational research, we use a finite element mathematical model of the thermally stressed state of the liner, refined during engine experiments.

Tribological assessment of NiCr, Al2O3/TiO2, and Cr3C2/NiCr coatings applied on a cylinder liner of a heavy-duty diesel engine

Internal combustion engines consume about 90% of fuel refined from crude oil which supplies 30% of the annual global flow of energy. Heavy-duty diesel engines are the primary source of power used in highways, marine, railroads, and power stations. The right coating can improve the tribological properties of cylinder liners and increase the mechanical efficiency of an engine. Also, it can help to extend the maintenance periods, and enhance the reliability of the vehicles. In this research, tribological and economic evaluations were performed for coated and uncoated substrates from a cylinder liner of a heavy-duty diesel engine, aiming to lower friction, wear rate, and maintenance cost. A reciprocating friction test was conducted under dry condition using Wolfram carbide (tungsten carbide) ball applied a 10 N normal load on a ball on disk geometry. The cylinder liner was made of gray cast iron, and the substrates obtained were coated with three different coating materials (Cr3C2/NiCr, NiCr, and Al2O3/TiO2) through the thermal spray and high-velocity oxy-fuel coating process. Tribological evaluations showed that the substrates coded with Al2O3/TiO2 and Cr3C2/NiCr had the lowest friction coefficient and wear rate. The most economical coating was Al2O3/TiO2, being able to supply about 61% lower coefficient of friction and 94% less wear rate relative to the uncoated sample, for the price of one-third of the Cr3C2/NiCr coating and one half of a new gray cast iron cylinder liner.

Influence of secondary phase particles Al2O3/SiC on the microstructure and tribological characteristics of AA7075-based surface hybrid composites tailored using friction stir processing

Recently, cylinder liners of automotive and aircraft engines are encountered severe wear due to piston slap occurred by the repeated sliding stroke of piston. This research focuses on providing an alternative material for cylinder liners, which can be obtained through friction stir processing on AA7075 with different weight ratios of reinforcements like Al2O3 and SiC. Friction stir processing is executed with a tool rotational speed of 1000 r/min and traveling speed of 56 mm/min at 2° tool tilt angle. The images of optical microscopy reveal the fine-grains with a homogeneous distribution of secondary phase particles and also offer decrement in particle clustering except at some localized regions. It is identified that addition of 3.7 wt.% Al2O3 + 3.0 wt.% SiC in AA7075 enhanced the microhardness about 33.96% higher than base matrix. Hence, wear resistance of the specimen is improved. Dry sliding wear behavior of specimens is analyzed using pin on disc at 20, 40, and 60 N load conditions to create the actual sliding behavior of piston on cylinder wall. Increasing the wt.% of Al2O3 particles enhanced the wear resistance of AA7075 surface hybrid composites at 20 N load due to the formation of protective tribofilm. Specimen with 3.7% Al2O3 + 3.0% SiC has better lubrication and load-bearing capacity that exhibits superior tribological behavior at 40 and 60 N. Higher Fe content of 5.44 wt.% has been obtained through spectroscopy analysis in S5, which is 8% and 6% higher than S3 (7.5% of Al2O3) and S7 (6% of SiC), respectively. The scratching action of this hard specimen on the counterpart brings more Fe content. Increase of Al2O3 particles paved the way for tribofilm formation and identified through scanning electron microscopy micrographs. The observation from worn specimens shows that finer wear debris had increased by adding more quantity of SiC particles due to abrasive wear mechanism.

Restoration of cylinder liners for automotive tractors engines in modern conditions

One of the most promising technologies for restoring machine parts and cylinder liners is electric spark treatment as the most versatile technology that provides high-quality restoration of worn parts with wear up to 0.5 mm. (Research purpose) The research purpose is in developing a technology for restoring various cylinder liners by means of electric spark processing, selecting optimal modes and electrode materials that allow improving the quality of repair and increasing the post-repair life of the sleeve. (Materials and methods) It was taken into account when conducting research aimed at restoring the geometric parameters of the sleeve, that the coating must have sufficient adhesion strength to the surface of the sleeve under mechanical, thermal loads and long-term operation. Laboratory studies of the adhesion strength of electric spark coatings on the separation (adhesive) and on the cut, as well as tribotechnical studies of interfaces were conducted. Authors have found by analyzing the results of operational tests of restored and new cylinder liners the prospects for using electric spark treatment of worn parts, including diesel engine liners. (Results and discussion) It was shown by laboratory studies of the adhesion strength of electric spark coatings with a 0.2 mm thick BrMKc 3-1 electrode to the working surface of cylinder liners that their separation strength (adhesive) was 20-40 megapascals, and the shear strength (cohesive) was 50-80 megapascals. It was found that this provides the required functional strength of coatings with maximum operational load. The article presents the results of comprehensive research in graphs and tables. (Conclusions) The research conducted in the CCP "Nano-Center" of the FSAC VIM and operational tests in the 2nd bus fleet of Moscow confirmed the principal possibility of effectively restoring cast iron liners (blocks) using the technology of electric spark processing.

Examining the role of hexagonal boron nitride nanoparticles as an additive in the lubricating oil and studying its application

Lubricating oil plays an important role in minimizing the friction and wear of many mechanical systems. The additives present in the conventional lubricant are inadequate to reduce the friction and wear of today’s mechanical systems. However, the use of these additives has a significant effect on the environment due to their fast chemical degradation. In recent years, nanoparticle-based lubricant has attracted great attention due to their friction reduction behavior. Therefore, it is of great importance to examine the role of nanoparticle addition in the conventional lubricant and its influence on the tribological characteristics of the mechanical systems. Hence, this research work focused on the formulation of hexagonal boron nitride nanoparticle-based nanofluids and its effect on the tribological characteristics of cylinder liner and piston rings of a realistic diesel engine. The different concentrations of hBN nanoparticle-based nanofluids were formulated and characterized using the ultraviolet–visible spectroscopy and the thermal gravimetric analysis. The results of the experimental analysis showed that hBN nanoparticles as an additive in the lubricating oil exhibited better anti-wear and friction reduction behavior than the conventional base oil 20W40.

Enhancement of Heat transfer of Cylinder liner and Coolant jacket for High powered Diesel engine

The cooling system of an Armoured Fighting Vehicles (AFV) is critical and complex when compared to other automobiles mainly because of the severe temperature and dust conditions in which they operate. For proper working of the engine, it is very important that the engine be maintained at optimum temperature during its operation to have desired performance levels. Usually high powered engines employ water cooled cooling systems with compact radiators. Also the cooling system in AFV Engine is very critical as the air space available is very less. This is due to the fact that the engine is enclosed in a compartment where the ram air due to vehicle movement cannot be used to cool the radiators. Hence any small improvement in the heat transfer improves the performance of the engine. The main aim of the study is to enhance the heat transfer between the engine liner and the coolant for AFV engines. The heat transfer rate is enhanced by modifications on the surface of the liner coolant interaction with an aim to induce turbulence in the coolant flow through the jacket. For each modification, the heat transfer coefficient is found out through CFD analysis in Ansys Fluent. The combustion temperatures and heat transfer coefficients obtained using simulation software AVL BOOST® were used to calculate the wall temperature of liner. Simulations on modified geometry of liner walls yielded up to a maximum of 18% improvement in heat transfer which is very significant.

Increase of strength of cast-iron cylinder liners of engines of road construction vehicles

Cylinder liners made of gray cast iron are quite widespread in the design of engines of road construction vehicles. The negative properties of this structural material include relatively low strength and high fragility. This increases the probability of both manufacturing and operational defects. Therefore, improving the performance of the considered parts is an urgent problem. A promising direction in this case is the use of chemical-and-thermal treatment. The aim of the work is to study the effect of chemical-and-thermal treatment of gray cast iron on strength. The paper investigates the strength of cast iron subjected to chemical-and-thermal treatment (thermal diffusion surface alloying). On the basis of experimental studies, the effect of the thickness of the hardened layer on the strength was studied. A numerical model is created in the Ansys software. The effect of the hardened layer on the strength of cylinder liners of engines of road-building vehicles is investigated.

Numerical modeling of thermophoretic deposition on cylinder liner of a diesel engine using a sectional soot model

Soot deposition on combustion chamber walls of a diesel engine is one of the key concerns among diesel engine manufacturers as it affects the durability and wear of the power cylinder components. The deposition of soot on the liner also gets scraped to the crank case and leads to soot in the lubrication oil. In this work, a modeling framework is presented to estimate the deposition of soot on the liner walls. Three-dimensional computational fluid dynamic combustion simulations are performed at two operating loads for a direct injection heavy duty diesel engine. A sectional soot model coupled with gas phase chemical kinetics is used to model soot in the combustion chamber. The combustion and soot models are validated by comparing in-cylinder pressure, heat release rate and soot mass from simulations with the experimental data. A thermophoretic soot deposition model is presented which transports soot from combustion to the liner walls. Detailed in-cylinder soot mass fraction contours are used to explain the deposition phenomenon. The deposition of soot on the liner is qualitatively compared to measured soot in the lubrication oil and a good agreement is observed. The proposed modeling framework shall be helpful for optimizing combustion systems to reduce degradation of lubrication oil.

Characterization of the friction and wear effects of graphene nanoparticles in oil on the ring/cylinder liner of internal combustion engine

Purpose This study aims to investigate the tribological characteristics of a Napier-type second piston ring against a cylinder liner in the presence of graphene nano-additives mixed into 5W40 fully synthetic engine oil. Design/methodology/approach Wear tests were carried out in the boundary lubrication condition using a reciprocating tribometer, and real engine tests were performed using a single spark ignition Honda GX 270 test engine for a duration of 75 h. Findings The experimental results of the tribometer tests revealed that the nano-additives formed a layer on the rubbed surfaces of both the piston ring and the cylinder liner. However, this layer was only formed at the top dead center of the cylinder liner during the engine tests. The accumulation of carbon (C) from the graphene was heavily detected on the rubbed surface of piston ring/cylinder liner, mixed with other additive elements such as Ca, Zn, S and P. Overall, the use of graphene nano-additives in engine oil was found to improve the frictional behavior in the boundary and mixed lubrication regimes. Abrasive wear was found to be the main mechanism occurring on the surface of both piston rings and cylinder liners. Originality/value Though many researchers have discussed the potential benefits of graphene as a nano-additive in oil to reduce the friction and wear in laboratory tests using tribometers, to date, no actual engine tests have been performed. In this paper, both tribometer and real engine tests were performed on a piston ring and cylinder liner using a fully formulated oil with and without graphene nano-additives in the boundary lubrication condition. It was found that a graphene nano-additive plays an active role in lowering the coefficient of friction and increasing surface protection and lubrication by forming a protective layer on the rubbing surfaces.

Exploring a possibility to control the stressed­strained state of cylinder liners in diesel engines by the tribotechnology of alignment

Our research into the formation of a functional copper-containing surface layer on parts of automobile engines by using an alignment tribotechnology has established a decrease in the wear of parts during their operation. It was found that the formed coating creates an elastic layer that reduces strains in a material of engine parts. Our experimental study of the coercive force of parts' working surfaces has confirmed a decrease in the accumulation of destructive stresses in the near-surface layers of a components' material. In turn, a comparative analysis of the obtained results by using a coercimetric method confirms that the proposed aligning tribotechnology leads to reduction of the stressed-strained state and makes it possible to improve wear resistance and enhance the technical condition of diesel engine cylinder liners: the magnitude of coercive force reduces by 7.5 %, while operating time increases by 16 %. In this case, at larger operating time: 254.8 thousand km against 220.5 thousand km, according to data on the coercive force (14.2…9.1) A/cm and (13.2…9.0) А/cm, it is almost in the same condition.The functional surface layer forms when introducing a composite oil to the tribotechnology of cold alignment of an automobile powertrain. We have proposed and implemented a circuit to connect electric current to components at an engine's cylinder-piston group as a result of studying the developed tribotechnology of alignment. The features of this scheme are that the constant electric current is supplied by the plus polarity, through the brush-collector node, to the crankshaft, and by the minus polarity, through the clamping contact, to the crankcase block.The research results suggest a possibility to control the internal strains and the subsequent magnitude of wear in a material of working heavily-loaded components of automobile powertrains provided they are serviced properly. The proposed tribotechnology of alignment could be of interest for both service departments at trucking companies and for car service stations.

Performance and emission characteristics analysis of thermal barrier coated diesel engine using palm biodiesel

Various research works are being undertaken around the world on the subject of thermal efficiency improvisation and emission reduction from diesel engines. This research work analyzes the performance and emission characteristics of a thermal barrier coated diesel engine which used palm biodiesel. The piston and cylinder liners were coated with equal percentages of alumina (Al2O3) and yittria-stabilized zirconia (YSZ) powder using plasma spraying coating method. The piston was coated with 100μm thickness and the two cylinder liners were coated with 150 and 200μm thicknesses and were used to analyze the performance and emission characteristics. Test results of the thermal barrier coated engine using palm biodiesel were compared with the results derived from the base engine. The tests revealed an increase of 3.8% specific fuel consumption (SFC) as an average when neat palm biodiesel was used in the base engine. Interestingly, the palm biodiesel used in the 150- and 200-μm thick thermal barrier coated engine was responsible for a significant decrease of the SFC by an average of 4.18% and 8.05% respectively. The brake thermal efficiency was found to decrease on an average of 1.02% when tests were run using the neat palm biodiesel in the base engine. But an average proportionate increase of 0.72% and 2.19% was visible when palm biodiesel was used in the tests conducted on the 150- and 200-μm thick thermal barrier coated engine. There was also an understandable brake specific reduction of 0.991g/kWh carbon monoxide (CO) emission and 0.025g/kWh unburned hydrocarbon (HC) levels. The nitrogen oxide (NOx) emission was observed as 14.06g/kWh in the 200-μm thick thermal barrier coated engine which was slightly higher when the results were compared with that of the uncoated engine. The novelty of this research investigation is based on the usage of yttrium-stabilized zirconia and alumina thermal barrier coating on the cylinder liner and piston head of engine. This is justified due to the fact that most of the previous investigations undertaken focused on the thermal barrier coating in the piston, valve, and cylinder head alone. The utility factor of the palm biodiesel (B 100) in the low heat rejection engine has also proved to be another significant and novel factor in the present investigation outlined in this paper. This is mainly due to the fact that the ongoing investigations in this realm concentrated only on blends of 20 to 30% of palm biodiesel with diesel fuel in the low heat rejection diesel engine.

Influence of the abrasive grain trajectory on the machining of thin-walled cylinder liners of internal combustion engines with variable kinematics of honing

Honing with variable kinematics has a number of advantages in comparison to traditional honing [1-19], such as less tool wear [12, 13], lower processing temperature [13], better surface quality [12, 13] and less deviation of cylindricity [13]. The article discusses the influence of the variable kinematics on the machining process.

Increasing the reliability of cylinder liners of marine diesel engines: problems and solutions

Increasing the reliability of cylinder liners of marine diesel engines: problems and solutions

Numerical analysis of gas flow through the labyrinth seal of piston rings of an automotive IC engine

In the paper a model of transient gas flows through the labyrinth seal: piston-rings-cylinder (PRC) has been presented. The results of calculations for a ring pack of three piston rings operating on a cylinder liner of a spark ignition internal combustion engine have been shown. The analysis of the gas dynamics and a parametric study considering this phenomenon has been carried out. It allowed evaluating the influence of the most important parameters of this sealing on the gas pressure acting on the rings and blow-by to the crankcase. The simulation results show the necessity of taking into account the following parameters: uneven wear of cylinder liner and its thermal and mechanical deformation, thermal deformation of piston rings, heat transfer between the flowing gas and the labyrinth walls, dynamics of axial ring displacements in piston grooves.