Engine Wear Research Articles

An experimental investigation on the long-term compatibility of preheated crude palm oil in a large compression ignition diesel engine

An experimental study was carried out on a large stationary compression ignition engine to evaluate the long-term compatibility and durability issues associated with the use of crude palm oil as fuel. Two different preheating temperatures (60 and 80 °C) were adopted to assess the potential improvements related to lower fuel viscosity. The results obtained, in terms of in-cylinder carbon deposits and engine wear, were compared with the results obtained using ordinary diesel fuel. For each fuel and preheating temperature, the engine was operated for 300 consecutive h, during which several engine lubricant samples were collected and analysed to determine soot and fuel contaminations, viscosity alterations, and the presence of different wear-related metals (measured by atomic absorption spectroscopy). At the end of each 300 h endurance test, the carbon deposits were scraped from engine cylinders and examined through thermogravimetric analysis (TGA). It was found that the use of crude palm oil caused a remarkable increment of in-cylinder deposits formation compared with ordinary diesel. The lubricant analysis also revealed a faster viscosity degradation and consequent stronger engine wear, above all with the lower preheating temperature. The results obtained confirmed that continuous engine operation (i.e., without a complete lubricant change) should be carefully reduced when fuelling with crude palm oil. Moreover, the findings obtained herein confirmed the favourable impacts of fuel preheating at 80 °C compared to 60 °C, i.e., reduced carbon deposits by 27% and extended engine operation time by 30%.

ПУТИ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ ТОНКОЙ ОЧИСТКИ МОТОРНОГО МАСЛА СОВЕРШЕНСТВОВАНИЕМ ФИЛЬТРОВАЛЬНЫХ НЕТКАНЫХ МАТЕРИАЛОВ В МАСЛООЧИСТИТЕЛЯХ СУДОВЫХ ДИЗЕЛЕЙ

The article presents the results of motor tests of mass production filtering elements and new ones with improved performance in marine diesel engines. The filtering elements help to increase the efficiency of cleaning the engine oil and to lessen the engine wear and carbonation. The extended diesel service life is directly connected to the quality of oil purification. There has been carried out the analysis of developing filter technology regarding to engine oil cleaning in lubrication systems of ship medium-speed internal combustion engines equipped with different oil cleaners on the vessels of the Far Eastern basin. There have been presented the methods of increasing the throughput, dirt capacity and service life, as well as the fineness and completeness of sifting filtering elements due to the use of new filter materials. The dependence of the oil filtration rate on the efficiency of its purification is shown. Oil purification process can be intensified by means of decreasing the rate of oil filtering. To obtain the optimal filtering rate it is necessary to choose the appropriate size of a filtering element. Nowadays, the production technology of filtering elements is constantly improving, parameters of filtering materials are being upgraded, such as porosity, specific capacity, etc. There have been proposed measures to improve the hydraulic and filtering characteristics of nonwovens from cellulose and synthetic fibers of different thicknesses with different fillers and binders, which increases the permeability of papers, the number of pores per unit surface and a narrower distribution in diameter. New scientific and technical solutions are presented, which increase the efficiency of oil use in diesel engines. The ways of reducing the wear rate of the main parts in the engine due to full-flow fine cleaning of lubricating oil providing economical resource-saving operation of the trunk diesel engines are shown. The Russian industry manufactures the full-flow filtering elements and filtering materials relevant to the best international analogues.

Trace Elements and Polycyclic Aromatic Hydrocarbons Variation Along the Guang-Shen Expressway Before and After the 2016 Qingming Festival in Guangzhou.

PM2.5 samples (particles with aerodynamic diameter < 2.5μm) were collected along the Guang-Shen expressway around the Qingming Festival, one of the most congested periods in China, which started from April 2-4, in 2016. Twenty-five trace elements and 16 priority polycyclic aromatic hydrocarbons (PAHs) of the samples were analyzed. Their major sources at different periods were identified. The concentrations of PAHs distinctly increased with growing traffic flow 2days before the Qingming Festival (March 31th and April 1st), decreased gradually on the first 2days of the 3-day festival (April 2nd and 3rd) and rose again on the last day (April 4th). The proportion changing of higher molecular weight containing 5- and 6-ring PAHs (HMW PAHs) closely related to the traffic flow variation were consistent with the concentration variation of PAHs during the experimental period. Indicators of gasoline/diesel engines emission, i.e., Mo, Co, Mn, and Pb showed similar concentration variation with PAHs. The concentrations of trace elements, mainly derived from wear instead of combustion process, such as Cu, Zn, Ti, and Sb, raised significantly during the rainy days. Incremental lifetime cancer risk (ILCR) values were calculated to evaluate the health risk caused by PAH around the Qingming Festival. The ILCR values increased by 3-10 times 2days before and on the last day of the festival comparing with other days, as a result of traffic related sources, including engine emission and wearing of tires. It concluded by recommending the necessity of traffic diversion to alleviate the health risk to drivers and nearby residents during important festivals.

Dust Loading Performance of a Novel Submicro-Fiber Composite Filter Medium for Engine.

Airborne dust can cause engine wear and contribute to engine gas emission. This study developed a novel submicro-fiber filter medium to provide protection to engines against dust. The wet-laid submicro-fiber medium was prepared by a dual-layer paper machine, and its dust loading performance was compared with other filter media during laboratory and field tests. During the laboratory tests, the dust holding capacity of the wet-laid submicro-fiber medium was 48% and 10% higher than that of the standard heavy-duty medium and electrospun submicro-fiber medium, respectively. During the field tests, the pressure drop of the wet-laid submicro-fiber filter was 45% lower than that of the standard heavy-duty filter after 10,000 km of operation. It was found that there were two crucial ways to design a better filter medium for protection against dust. Firstly, the surface loading rather than the depth loading was preferred for dust filtration. The submicro-fiber layer kept large amounts of dust particles from penetrating into the depth of filter medium. Secondly, particles were captured preferably by fibers rather than pores. The unique fibrous structure of the wet-laid submicro-fiber medium made more particle deposition take place on fibers via interception and inertial impaction.

Wear Monitoring of the Trucks

The article deals with the monitoring of wear of truck oils in order to determine their wear. The research part is focused on engine oils, tribology and analytical methods for evaluation of oil degradation by abrasion particles. Thanks to these non-invasive technologies for monitoring and analyzing engine wear trends, an optimum oil change interval can be effectively set. The experiment analyzes engine oil samples from trucks and found the values of metal particles. Reference values for oil degradation levels are determined based on trend analysis. Metal abrasion particles and total impurities are determined and the state of the oils is evaluated experimentally.Optimal oil exchange iterval must be adjusted based on experiments. Wear of the truck engines is very individual with respect to the service life of the oil. The shortening of the interval is suggested with respect to the evaluation of the experiment. The aim of the article is to minimize the negative effects of abrasion during truck operation.

ОПТИМИЗАЦИЯ УГАРА МОТОРНОГО МАСЛА В СУДОВОМ ДИЗЕЛЕ С ВЫСОКИМ НАДДУВОМ ПО КРИТЕРИЮ ИЗНАШИВАНИЯ

The results of modeling the impact of oil burning on the condition of the ship forced trunk piston diesel engine when using lubricants with different operating properties. The dependence of wear rate on oil fume, the quality of used lubricants and marine diesel forcing is obtained by modeling wear using the theory of planning experiments. The area of minimal wear has been determined. There has been detected the most efficient waste oil providing favorable conditions for resource-saving operation of the internal combustion engine. It is inferred that reduction of engine oil fume changes the main parameters of its aging. At the same time, the intensity of oil aging in main directions and of engine wear reduce from 0.75 to 2.25 g/(kW∙h), whereas the fume increases. Its further increase is accompanied by an increase in the rate of oil aging and engine wear. The detected "fracture" depending on И( g y) after passing the border g yopt = 2.25-2.5 g/(kW∙h) is stipulated by different ratio of oil exchange in the lubrication system and the ingress of gases into the crankcase. There has been determined the degree of oil burning, at which sludging and lacquer formation of the internal combustion engine is least intense. The smallest carbon deposits on pistons and in the crankcase of the engine can be observed when the diesel engine is operating in the zone of optimal carbonation. Experimentally, the dependence of tribotechnical properties, in particular, wear of insoluble products of oil aging has been detected at different degrees of oil burning. It is revealed that these characteristics also depend on the quality of the used fuels and lubricants and the conditions of formation and turnover of the oil film on the mirror of the cylinder, the thermal effect on it of the engine workflow. The result of simulation is the prediction of resource-saving operation of marine trunk diesel engines by maintaining oil fume at the optimal level.

Tribology of Wire Arc Spray Coatings under the Influence of Regenerative Fuels

In order to further optimize the efficiency of today’s internal combustion engines, specific coatings are used on functional surfaces to reduce internal engine friction and wear. In the current research project, oxymethylene ether (OME) is discussed because it is CO2 neutral and has a strong soot-reducing effect as a fuel or fuel additive. In some operational regimes of the internal combustion engine a dilution of engine oil by fuel must be assumed. In this paper, the frictional contact between piston ring and cylinder raceway is modelled using a pin-on-disk tribometer and the friction and wear behavior between a diamond-like carbon coating (DLC) and a thermal spray coating is characterized. The wear of the spray layer could be continuously detected by radionuclide technology (RNT). With the aid of photoelectron spectroscopic measurements (XPS), the steel thermal spray coating was chemically analyzed before and after the tribometer tests and the oxidative influence of OME was investigated. In addition, confocal microscopy was used to assess the topographies of the specimens. The measurements showed that the addition of OME to the lubricant reduced the viscosity and load-bearing capacity of the lubricating film, which led to an increase in the coefficient of friction. While almost no wear on the pin could be detected at 10% OME, the first visible material removal occurs at an OME content of 20% and the layer delaminated at 30% OME. The evaluation of the RNT wear tests showed that both the tests with engine oil and with engine oil plus 20% OME achieved very low wear rates. No corrosion of the thermal spray coating could be detected by XPS. Only the proportion of engine oil additives in the friction track increased with increasing OME concentration.

Study of Important Performance Characteristics of Commercially Available Two and Four Stroke Engine Lubricants

Background/Objectives: In this paper, a complete study and experimentation of engine lubricants or engine oils with the help of viscosity grades through the mathematical formulas and experimental data having different viscosity grade of lubricants at different temperature. Methods/Statistical Analysis: For analyze the viscosity, density and thermal conductivity with the assistance of Redwood viscometer, Hydrometer and Transient hot-wire method, and reciprocal of thermal conductivity (k) is called thermal resistivity (r). Engine oils 10W40, 10W30, and 15W40 are selected for testing. Findings: in these different types of engine oil tests, four parameters (viscosity, thermal conductivity (k), density, thermal resistivity and 126 experiments were performed with four different temperature 30°C, 40°C, 50°C, and 60°C, which shows the comparisons of different engine lubricants at same viscosity grade. Applications: The oil lubrication pollution against the motor part wear, leading the loss of engine performance and life, the dynamic engine oil or lubricant oil films confine moving portion surfaces cause a the significant bit of the engine wear. In the engine lubrication system, viscosity plays important role, wearing of the automated parts. There are different lubricants are in market having different viscosity grades. A mechanical or automated engine is a completed machine; it comprises of several moving parts. The moving part of the automated or mechanical engine is driven under different temperature and pressure ranges to reduce the friction or erosion and control wear. Engine oil plays the important role, so the oil action and specifications reduce the friction or erosion and control the engine wear behavior, the viscosity is one of the most important parameter of the engine oil specifications, the viscosity comprises and shows the number of forces or power between the oil particles. Keywords: Friction Loss, Lubricant Oils (10W40, 10W30, 15W40), Oil Density, Oil Viscosity, Optimization, Two and Four Stroke Engine

NUMERICAL INVESTIGATION OF THE EFFECTS OF GEOMETRICAL PARAMETERS ON THE VORTEX SEPARATION PHENOMENON INSIDE A RANQUE-HILSCH VORTEX TUBE USED AS AN AIR SEPARATOR IN A HELICOPTER’S ENGINE

Air separators are fitted to helicopter engine intakes to remove potentially harmful dust from the influent air. Their use is necessary in desert environments to eliminate the risk of rapid engine wear and subsequent power deterioration. However, their employment is concomitant with an inherent loss in inlet pressure and, in some cases, auxiliary power. There are three main technologies: vortex tubes, barrier filters, and integrated inlet particle separators. In this work, a vortex tube is investigated numerically. The study was conducted on the number and axial angle of inlet nozzles. Two and three-dimensional models are investigated at a steady state condition then the standard k-ε turbulence model is utilised for determining the flow and temperature fields. The finite volume method base on a Computational Fluid Dynamic (CFD) model is verified through the comparison with experimental data and numerical results of a vortex tube, reported in literature sources. Increasing the number of inlet nozzles, increases the sensitivity of the temperature reduction and the highest possible temperature reduction can be obtained. A vortex tube with an axial angle inlet nozzle of yields better performance. The numerical simulation results indicated that the CFD model is capable of predicting the vortex separation phenomenon inside a Ranque-Hilsch vortex tube with different geometrical parameters.

A switched dynamical system approach towards the economic dispatch of renewable hybrid power systems

This paper considers an economic dispatch problem of renewable hybrid power systems. According to the analysis of the renewable hybrid power system dynamic behavior, the problem is modelled as an optimal control problem of switched dynamic systems. As is known to all, the frequent switching may cause that the engine wear is increased, and the service life is reduced. Then, some switching constraints are imposed to the switched dynamic system model. However, these switching constraints lead to a non-connected feasible region for the optimal control problem with unknown switching instants, integer variables, and continuous variables. Thus, it is difficult to solve such problem by using conventional optimization methods, such as sequential quadratic programming. To overcome this difficulty, by using the time-scaling transformation technology and introducing an auxiliary continuous vector derive a more tractable equivalent problem, in which the variable switching instants and the switching sequence are replaced with conventional continuous parameter variables. Then, based on an exact penalty function, an alternative computational method is developed for solving the problem. Finally, three numerical examples are solved by using the proposed algorithm. The numerical results show that although the optimal costs with switching constraints slightly higher than the optimal costs without switching constraints, the proposed algorithm can effectively avoid the additional switches. In addition, the numerical results also show that the switched dynamical system approach is low time-consuming and obtains a better cost function value than the existing approaches.

Impact of Bio-diesel fuel on Durability of CI Engines – A Review

Bio-diesel is a sustainable, renewable and alternate fuel for CI Engines. The use of bio-diesel produces various durability issues on key components of CI engines. For durability studies, the aspects considered are injector coking, carbon deposition on piston, lubricity of engine oil, wear and tear of piston and cylinder walls and corrosion of engine parts they come in contact with fuel. In this work, reports about the durability aspects, published by highly rated journals in scientific indexes, have been cited. From these reports, the effect of bio-diesel on engine durability are surveyed and analysed. The use of bio-diesel leads to injector coking, increased carbon deposition on piston, decreased viscosity of the lubricating oil and fuel dilution, increased engine wear and increased corrosion.

Chemical analysis of engine oils as an indicator to estimate the rate of wear

Current research aims to inspect the chemical analysis of engine oils as an indicator of wear in engine. The novelty of work is to test lubricating oil quality and to determine the wear rate in a simple way by taking oil sample of 10 cm3 and analyzed it in about 5 minutes. This can be done during the operation of equipment without need to stop them, furthermore, this method is a quick indicator of the need to change oil as soon as the initial evidence of wear in the oil molecules. Fresh and used oil samples were chemically analyzed for its elemental analysis for additive elements such as Fe, Cr, pb, Cu, Sn, Al, Ti and Zn, to clarification the wear generation of engine from the contamination present in the lubricating oil. Obtained results showed that increasing percentage of particles of Fe, Cr, pb, Cu, Sn, Al, Ti and Zn metals accompanied by the wear caused in these metals. Height ratio in element Si was not too high this indicated the quality and efficiency of air filters after 100 hours working. Salts such as Na, Ca have increased, but Ba decreased by chemical action at hot temperature of engine.

Ultrafine particle emissions from modern Gasoline and Diesel vehicles: An electron microscopic perspective

Ultrafine (<100 nm) particles related to traffic are of high environmental and human health concern, as they are supposed to be more toxic than larger particles. In the present study transmission electron microscopy (TEM) is applied to obtain a concrete picture on the nature, morphology and chemical composition of non-volatile ultrafine particles in the exhaust of state-of-the-art, Euro 6b, Gasoline and Diesel vehicles. The particles were collected directly on TEM grids, at the tailpipe, downstream of the after-treatment system, during the entire duration of typical driving cycles on the chassis dynamometer. Based on TEM imaging coupled with Energy Dispersive X-ray (EDX) analysis, numerous ultrafine particles could be identified, imaged and analyzed chemically. Particles <10 nm were rarely detected. The ultrafine particles can be distinguished into the following types: soot, ash-bearing soot and ash. Ash consists of Ca, P, Mg, Zn, Fe, S, and minor Sn compounds. Most elements originate from lubricating oil additives; Sn and at least part of Fe are products of engine wear; minor W ± Si-bearing nearly spherical particles in Diesel exhaust derive from catalytic coating material. Ultrafine ash particles predominate over ultrafine soot or are nearly equal in amount, in contrast to emissions of larger sizes where soot is by far the prevalent particle type. This is probably due to the low ash amount per volume fraction in the total emissions, which does not favor formation of large ash agglomerates, opposite to soot, which is abundant and thus easily forms agglomerates of sizes larger than those of the ultrafine range. No significant differences of ultrafine particle characteristics were identified among the tested Gasoline and Diesel vehicles and driving cycles. The present TEM study gives information also on the imaging and chemical composition of the solid fraction of the unregulated sub-23 nm size category particles.

Effects of ethanol content on cast iron cylinder wear in a flex-fuel internal combustion engine–A case study

The localized wear within a four-cylinder automotive spark-ignition internal combustion engine was investigated using a dynamometer durability test. The test engine was equipped with flexible fuel technology, popularly known as “Flex-Fuel”, capable of operating under any mixture of gasoline and ethanol in the fuel. A 2-D profilometer analysis was conducted on engine block specimens from the Top-Dead-Center (TDC) and Bottom-Dead-Center (BDC) positions in order to identify localized wear characteristics. The profiles have shown localized wear dependence in regions of the cylinder bore, as did comparative results between two test conditions: (i) an engine fueled with local gasoline (E25) and (ii) an engine fueled with ethanol (E100). Selected localized wear regions have been characterized using scanning electronic microscopy. Complementary piston ring wear analysis was carried out to assess the remaining coating thickness at the end-of-test. The test with ethanol resulted in the highest localized wear, which occurred at the Bottom-Dead-Center position. A condensed literature review was conducted. An attempt was made to correlate the observed wear features with possible mechanistic theories found in the wear literature. Characterization results indicated that three-body abrasion by carbon residues and piston ring particles is one of the important mechanisms contributing to the cylinder bore wear.

OPERATIONAL EVALUATION OF PISTON-RINGS-CYLINDER LINER ASSEMBLY WEAR IN HIGH POWER MARINE DIESEL ENGINES

This paper presents an operational evaluation of piston-piston rings-cylinder liner (PRC) assembly wear in marine diesel engines of high power. It is based on visual inspection through cylinder liner scavenge ports. Clearance measurements of piston rings in piston grooves and piston ring gap measurements were used to evaluate the extent of wear of the PRC assembly. Moreover, it is shown that piston ring gap measurements can be used as a reference parameter in wear trend analysis to predict the length of time periods between overhauls (TBO). Furthermore, it has been shown that controlling the wear of chromium (protective) layers of piston ring working surfaces by measuring their thickness with induction and eddy current methods is highly useful. They were accepted as a source of information on PRC lubrication correctness and as a symptom of its technical condition. Factors indicating the necessity of an overhaul and introducing operational methods of improving working conditions between the tribological pair – liner and piston rings have been determined.

Adaptive Engine Torque Compensation with Driveline Model

Engine net torque is the total torque generated by the engine side, and includes the fuel combustion torque, the friction torque, and additionally the starter motor torque in case of hybrid vehicles. The engine net torque is utilized to control powertrain items such as the engine itself, the transmission clutch, also the engine clutch, and it must be accurate for the precise powertrain control. However, this net torque can vary with the engine operating conditions like the engine wear, the changes of the atmospheric pressure and the friction torque. Thus, this paper proposes the adaptive engine net torque compensator using driveline model which can cope with the net torque change according to engine operating conditions. The adaptive compensator was applied on the parallel hybrid vehicle and investigated via MATLAB Simcape Driveline simulation.

The effect of friction force and cavitation on wear in piston-cylinder assemblies

Both in engines and test rigs, cavitation in piston-ring lubrication is a subject studied by many researchers in the past. Although there is no sufficient evidence of cavitation erosion on the surface of the liner, this phenomenon is studied as part of the lubricant transport process. During the transport process the lubricant enters the combustion chamber. The combustion products of consumed oil might contribute to exhaust gas emissions and with emission legislation becoming more stringent, it is important that oil consumption is reduced to the lowest level possible. The role of the piston-rings is becoming more complex with the imposed requirements for lower oil consumption and friction. The piston-ring pack role on engine performance, durability and wear, is becoming on the other hand, more demanding. Between the piston-ring and cylinder liner, cavitation occurs as a result of two-phase liquid flow. Cavitation has long been recognized to degrade performances in most engineering applications and its effect in piston-ring lubrication is that it alters the oil film pressure profile, generated at the converging-diverging wedge of the piston-ring. An area of the piston-ring surface is void, corresponds to subatmospheric pressures and thus, the piston-ring load capacity is altered. Two experimental rigs were used, a simplified single-ring test rig that simulates the piston-ring liner movement at speeds corresponding to idle but the movement is reversed and a single cylinder diesel engine that was used for visualization results only, after the necessary modifications.

CURRENT STATE AND PROSPECTS OF INCREASING THE RELIABILITY OF TRIBODIAGNOSTICS IN ASSESSING TECHNICAL CONDITIONS OF THE OIL LUBRICATION SYSTEMS OF GAS-TURBINE AIRCRAFT ENGINES

The issues regarding the reliability of assessing health of the oiled joints of aircraft gas turbine engines (GTE) proceeding from the results of spectral and ferrographic measurement of the parameters of wear particles are considered. It is shown that, due to design features of the oil system analysis of the oil sample does not provide enough information about the wear processes in the GTE joints. Growth of the number of diagnostic parameters (particle concentration, form and size) does not significantly in- crease the reliability of health assessment, whereas analysis of the oil filter wipe sampling provides full information about engine wear processes. The main measurement instrumentation requirements are considered. High reliability of diagnostic results can be attained when the parameters of wear particles are measured over the full range of their variation. Issues regarding the recurrence of engine health assessment in case of using fine-meshed oil filter with 600-h lifetime are discussed. The use of expendable oil filters with a diagnostic layer can solve the problem. Diagnostic potentials of some promising methods of assessment and prognosis of the oiingl system health in aircraft GTE are evaluated.

Short term endurance results on a single cylinder diesel engine fueled with upgraded bio oil biodiesel emulsion

This paper deliberates the endurance test outcomes obtained from a single cylinder, diesel engine fueled with an upgraded bio oil biodiesel emulsion. In this investigation a bio oil obtained by pyrolysis of woody biomass was upgraded with acid treatment. The resulted bio oil was emulsified with addition of biodiesel and suitable surfactant which is termed as ATJOE15. The main objective of the endurance test was to evaluate the wear characteristics of the engine components and lubrication oil properties, when the engine is fueled with the ATJOE15 emulsion. The photographic views taken before and after the end of 100 hrs endurance test, and visual inspection of the engine components, wear and carbon deposit results, are discussed in this paper.

&lt;b&gt;Analysis of lubricant oil contamination and degradation and wear of a biogas-fed otto cycle engine

The increasing deployment of biodigesters for the treatment of waste on farms and the use of the biogas generated in the production of energy have highlighted the need for knowing the influence of this fuel on internal combustion engines. This study aimed to analyze the influence of filtrated biogas on lubricant oil contamination and degradation, as well as on engine wear and corrosion. Lubricant oil samples were collected every 75 engine operating hours (EOH) and then correlated between each other and with a sample of new oil, determining the elements present in the biogas that contribute to lubricant oil contamination and degradation, as well as lubricant oil performance in the course of EOH and engine wear. The results demonstrate that hydrogen sulfide affects the performance of the lubricant oil and engine wear. Among the metals, we observed that the copper concentration exceeded the maximum limit recommended in the literature. As for the additives, the variation in concentrations of magnesium impacted on lubricant performance. By monitoring lubricant oil quality were able to extend the engine oil change interval of this study by 50%, what resulted in a savings of 33.3% in the cost of lubricant per hour worked.