Automotive Engine Research Articles

Microstructure and Mechanical Properties of Mg-Al-La-Mn Composites Reinforced by AlN Particles.

The Mg-Al-RE series heat-resistant magnesium alloys are applied in automotive engine and transmission system components due to their high-temperature performance. However, after serving at a high temperature for a long time, the Al11RE3 phase coarsened and even decomposed, while the Mg17Al12 phase grew and dissolved, which limits the service temperature of Mg-Al-RE series heat-resistant magnesium alloys to a maximum of 175 °C. In this study, a new preparation method for in situ AlN particles was presented. The AlN/Mg-4Al-4La-0.3Mn composites were prepared by a master alloy and casting method. The effects of various contents of AlN (0.5-3.0 wt.%) on the microstructure and mechanical properties of the Mg-4Al-4La-0.3Mn (AE44) alloy at room (25 °C) and high temperatures (150-250 °C) were investigated. Microstructure analysis revealed that the inclusion of AlN led to a reduction in both the grain size and second phase size in the AE44 alloy, while also improving the distribution of the second phase. The average grain size, Al11La3 phase, Al2La phase, and Al3La phase of the 2.0 wt.% AlN/AE44 composite were 135.7, 9.6, 1.9, and 12.6 μm, respectively, which were significantly lower than those of the AE44 matrix alloy (179.8, 12.6, 3.3, 17.8 μm). The refinement was attributed to the ability of AlN particles to serve as heterogeneous nucleation cores for α-Mg and, at the same time, impede the growth of the solid-liquid interface, eventually leading to grain refinement. With the increase in the AlN content, the mechanical properties of composites initially exhibited an increase at both room and high temperatures, followed by a subsequent decrease. When the AlN content was 2.0 wt.%, the composite exhibited optimal strength and plasticity matching. At room temperature, the TYS, UTS, and EL values of the 2.0 wt.% Mg-4Al-4La-0.3Mn composite were 96 MPa, 175 MPa, and 7.0%, respectively, which were increased by 26 MPa, 27 MPa, and 0.7% when compared with the base alloy. The TYS of the 2.0 wt.% Mg-4Al-4La-0.3Mn composite at 150 °C, 200 °C, and 250 °C were 17 MPa, 14 MPa, and 22 MPa higher than those of the matrix alloy, respectively. The main strengthening mechanisms were second phase strengthening, load transfer strengthening, and thermal mismatch strengthening. At elevated temperatures, AlN particles effectively pinned the grain boundaries, inhibiting their migration, and hindered dislocation climbing, resulting in excellent mechanical properties of the composites at high temperatures. This study contributes to the advancement of in situ AlN particle preparation methods and the exploration of effects of AlN on the properties and microstructure of Mg-Al-RE alloys at high temperatures (150-250 °C).

Teaching Strategies for Automotive Engine Electronic Control System Testing and Maintenance Course under the “1+X” Certificate System

With the continuous development of China’s economy, cars have become the most common means of transportation for people. However, due to this impact, the contradiction between the market demand for after-sales services such as car testing and maintenance and the actual supply of professional technical personnel has become increasingly prominent. Therefore, strengthening the education reform of automotive inspection and maintenance professional technology has become an important task for major vocational colleges. The “1+X” certificate system has become a new norm in vocational education reform in China due to its significant advantages in cultivating students’ professional knowledge and skills to obtain professional skills certificates. Based on this, this article takes the course of automotive engine electronic control system testing and maintenance as an example to explain the practical significance and strategies of course teaching based on the “1+X” certificate system, aiming to further promote professional teaching reform and provide some reference for colleagues.

Tenfold Enhancement of Wear Resistance by Electrosynthesis of a Nanostructured Self‐Lubricating Al2O3/Sn(S)MoS2 Composite Film on AlSiCu Casting Alloys

Enhancing tribological performance through nanostructure control is crucial for saving energy and improving wear resistance for diverse applications. We introduce a new electrochemical approach that integrates aluminum (Al) anodization, tin alternating current (AC) electrodeposition, and anodic MoS2 electrosynthesis for fabricating nanostructured Al2O3/Sn(S)MoS2 composite films on AlSiCu casting alloys. Our unique process uses Sn‐modified MoS2 deposition to form robust solid lubricant MoS2–SnS electrodeposits within the nanochannels and microsized voids/defects of anodic alumina matrix films on the base materials, resulting in a bilayered Al2O3/SnSMoS2 and MoS2–SnS–Sn composite film. The AC‐deposited Sn enhances conductivity in the anodic alumina matrix film, acts as catalytic nuclei for Sn@SnS@MoS2 core‐shell nanoparticles and a dense top layer, and serves as a reductant for the direct synthesis of hybrid solid lubricant MoS2–SnS from MoS3 by anodic electrolysis of MoS42− ions. The resulting nanocomposite film provides a two‐fold increase in lubricity (friction coefficient (COF) μ = 0.14 ⇒ 0.07) and a ten‐fold improvement in wear resistance (COF μ < 0.2) compared to conventional Al2O3/MoS2 film formed by anodizing and reanodizing. The effectiveness of the Al2O3/Sn(S)MoS2 composite is further validated through real automotive engine piston tests.

Multi-Scale and Irregularly Distributed Circular Hole Feature Extraction from Engine Cylinder Point Clouds

The circular hole structures on automotive engines possess stringent mechanical processing requirements, so it is of vital importance to perform quality inspections on all manufactured circular hole structures. The detection of circular holes on automotive engines presents a significant challenge due to their numerous, multi-scale, and irregular distribution. Additionally, the data pertaining to circular holes is often incomplete, further complicating the detection process. In this paper, we proposed a multi-scale and irregularly distributed circular hole detection method for engine cylinder blocks, which enables the efficient extraction of all hole feature points within the engine, thereby facilitating quality inspection. First, the utilization of compartmentalization analysis techniques enhances the perceptual capacity for internal hole features from various angles. Second, by employing curvature center contractility method, hole-wall points are contracted towards their circular center positions, further enhancing the identification accuracy of small holes and holes with missing data. The proposed method is tested on both synthetic data and raw data, and compared with existing extraction and circular hole fitting methods. The experiment results demonstrate that compared to other methods, our method achieves the best feature point detection accuracy and hole primitive parameter calculation accuracy. Notably, even in special situations such as those with insufficient hole points and rounded structures, our method maintains exceptional discriminative capability and stability.

Efficiency of oxygenates on increase of octane number of reforming gasoline

At present, gasoline occupies one of the leading places among primary energy sources. The need of mankind in it, in its high quality, is greater than in any other fraction of hydrocarbons. Therefore, very high requirements are made to the operational properties of automobile gasoline, and the problem of improving the quality of gasoline is one of the urgent problems of the chemical industry. Modern vehicles require fuel with a high-octane number with properties preventing detonation and having octane numbers of 92, 95 and 98 for engines. High anti-detonation performance can be achieved through complex gasoline processing using catalytic cracking, isomerization and alkylation methods or by adding special high-octane additives to fuel. The world's leading trend in improving the environmental and performance characteristics of motor gasoline is the use of multifunctional additives, in particular oxygenates – compounds containing oxygen (such as alcohols, ketones, esters and others). The use of oxygen-containing components (oxygenates) is one of the promising ways to produce high-octane gasoline. Currently, in industrialized countries, oxygenates are actively used as a preferred substitute for organometallic anti-detonation additives and components of high-octane gasoline. In the presented work the properties of a new oxygenate - dimethyl ethynylcarbinol (DMEC), as an additive that increases the octane number of gasoline, are investigated. The study of the effect of oxygenates as methyl tert-butyl ether (MTBE) and DMEK on increasing the octane number of reforming gasoline showed that the increase in the octane number of gasoline when adding DMEK and binary additive is higher than when adding MTBE. According to the results of research, tertiary acetylene alcohol - DMEK can be offered as an oxygen-containing additive for automobile gasoline. The use of DMEK allows to expand the resources of high-octane components, reduce the toxicity of gasoline and exhaust gases, increase the production of high-quality commercial gasoline for automotive engines.

EFFECT OF PRECIPITATION HARDENING ON MICROSTRUCTURE OF 17-7 PH STEEL WITH MODIFIED CHEMICAL COMPOSITION

<p>Steel 17-7PH is austenitic-martensitic steel with high strength, hardness, and resistance to creep, and<br />corrosion. It is designed for aerospace components, but can also be used for other applications that require<br />high strength and corrosion resistance, as well as leaf springs for operation at temperatures up to 316 °C. It<br />can be used in a solution-treated or heat-treated state to obtain a wide range of property values. This<br />paperwork shows that modification of the contents of alloying elements with a narrower interval of Cr, Ni,<br />and Al can be obtained from austenitic-martensitic steel 17-7PH which by, a subsequent heat treatment,<br />can have values of mechanical and chemical properties required for components of an automotive engine.<br />Chromium is an alphagenic alloying element that stabilizes the ferrite region, nickel is a gammagenic<br />alloying element that stabilizes austenite and gives these steels good strength and toughness, even at low<br />temperatures and aluminum increases corrosion resistance in low-carbon corrosion-resistant steels<br />Research has determined the most suitable interval of Cr, Ni, and Al, which in combination with the<br />cryogenic heat treatment RH950 at -50 °C gives the mechanical and chemical properties that meet the<br />requirements for steel with standard chemical composition.</p>

Numerical investigation of heat and mass transfer study on MHD rotatory hybrid nanofluid flow over a stretching sheet with gyrotactic microorganisms

This study signifies the advancing reader’s understanding of complex fluid dynamics, offering insights crucial for optimizing heat transfer processes, environmental engineering applications, and biomedical technologies. The focus of this work is to examine the heat and mass transference properties of electrically conductive hybrid nanofluid flow on a bi-directional stretching surface with gyrotactic microorganisms. The effects of thermophoresis, thermal radiation, Brownian motion, heat source, and chemical reaction are incorporated into the problem. The sheet is rotated about the z-axis with ω as its velocity. The modeled equations are changed to dimensionless form with the use of similarity variables and are then solved by employing the homotopy analysis method (HAM). It is concluded that the larger rotation factor boosts the velocity plot. Similarly, the thermal radiation and thermophoretic factor heighten the thermal gradient of the hybrid nanofluid. From the computed data, it is revealed that the microorganism plot shows a declining behavior against the Peclet and Lewis numbers. The findings of this work help in the optimization of cooling systems in electronics, power plants, and automotive engines by enhancing heat transfer efficiency. Moreover, in biomedical engineering, understanding microorganism behavior in fluid flow is critical for developing advanced drug delivery systems and biomedical diagnostics.

Experimental investigation on backfire occurrence, duration and termination in a hydrogen-fueled automotive spark ignition engine

The present study investigates the occurrence, duration, and termination of backfire in a hydrogen-fueled automotive spark ignition engine. Backfire is a pre-ignition phenomenon that originates from the cylinder and the flame travels towards the intake manifold of the engine during the suction stroke. A high-speed camera was used to capture the real-time backfire images during the engine running. The simultaneous acquiring of the intake manifold and in-cylinder pressure was used to define the origin, duration, and termination of backfire. The probability of backfire occurrence rises with the increase in torque at constant speed, the increase in speed (at constant torque), high equivalence ratio, and the increase in torque with the decrease in speed (at constant brake power). The critical exhaust gas temperatures (EGT) identified for backfire initiation are in the range of 765 °C to 955 °C for speeds from 2000 rpm to 4900 rpm. A correlation of backfire occurrence number (BON) for the prediction of backfire occurrence was developed using experimental results, where BON greater than or equal to zero, indicates backfire occurrence. The backfire is characterized using backfire ignition delay, expansion, convergence and termination. The average backfire propagation velocity calculated using high-speed images is found to be 179.3 m/s corresponding to a Mach number of 0.52 at an equivalence ratio of 0.5 and hence, backfire under varied speed can be characterized as deflagration. Simultaneous acquiring of pressure was found reliable approach for calculating backfire propagation velocity. Lastly, backfire was suppressed using forced air induction at a reactant velocity of 4.5 m/s. This study’s results could be useful for the prediction of backfire occurrence and backfire velocity in hydrogen-fueled engines.

Heat and Mass Transformation of Casson Hybrid Nanofluid (MoS2 + ZnO) Based on Engine Oil over a Stretched Wall with Chemical Reaction and Thermo-Diffusion Effect

This study investigates the potential of a hybrid nanofluid composed of MoS2 and ZnO nanoparticles dispersed in engine oil, aiming to enhance the properties of a lubricant’s chemical reaction with the Soret effect on a stretching sheet under the influence of an applied magnetic field. With the growing demand for efficient lubrication systems in various industrial applications, including automotive engines, the development of novel nanofluid-based lubricants presents a promising avenue for improving engine performance and longevity. However, the synergistic effects of hybrid nanoparticles in engine oil remain relatively unexplored. The present research addresses this gap by examining the thermal conductivity, viscosity, and wear resistance of the hybrid nanofluid, shedding light on its potential as an advanced lubrication solution. Overall, the objectives of studying the hybrid nanolubricant MoS2 + ZnO with engine oil aim to advance the development of more efficient and durable lubrication solutions for automotive engines, contributing to improved reliability, fuel efficiency, and environmental sustainability. In the present study, the heat and mass transformation of a Casson hybrid nanofluid (MoS2 + ZnO) based on engine oil over a stretched wall with chemical reaction and thermo-diffusion effect is analyzed. The governing nonlinear partial differential equations are simplified as ordinary differential equations (ODEs) by utilizing the relevant similarity variables. The MATLAB Bvp4c technique is used to solve the obtained linear ODE equations. The results are presented through graphs and tables for various parameters, namely, M, Q, β, Pr, Ec, Sc, Sr, Kp, Kr, and ϕ2* (hybrid nanolubricant parameters) and various state variables. A comparative survey of all the graphs is presented for the nanofluid (MoS2/engine oil) and the hybrid nanofluid (MoS2 + ZnO/engine oil). The results reveal that the velocity profile diminished against the values of M, Kp, and β, and the temperature profile rises with Ec and Q, whereas Pr decreases. The concentration profile is incremented (decremented) with the value of Sr (Sc and Kr). A comparison of the nanofluid and hybrid nanofluid suggests that the velocity f′ (η) becomes slower with the augmentation of ϕ2* whereas the temperature increases when ϕ2* = 0.6 become slower.

EXPERIMENTAL INVESTIGATION OF THE VIBRATION-REDUCTION CHARACTERISTICS OF THE SHAFT COATING FOR A TURBOCHARGER

A turbocharger is a system that is fitted to automotive engines to increase performance and efficiency by taking air at atmospheric pressure, compressing it to a higher pressure and passing the compressed air into the engine via the inlet valves. A turbocharger consists of a turbine and a compressor impeller interconnected with a shaft supported in most cases by journal bearings. The shaft is one of most crucial components of a turbocharger system and it operates at high speed. The shaft vibrations are an inherent phenomenon and they are travelling to the surrounding structure, effecting the stability and reliability of the turbocharger system. The selection of the appropriate shaft-material property is a critical parameter among the parameters that affect the vibration of the system. This study focuses on exploring whether it is possible to reduce the shaft vibration using different types of coating materials, including aluminum chromium nitride (AlCrN), titanium nitride (TiN) and aluminum titanium nitride (AlTiN), each having thicknesses of (2, 4, and 6) µm, for a shaft made of AISI 4140 alloy steel. The inherent natural vibration properties, such as the resonant frequencies, damping, and mode shapes of the turbocharger shaft with and without coating, were obtained by conducting an experimental modal analysis through measurements of the frequency-response function, which is about curve fitting the data using a predefined mathematical model of the turbocharger shaft. The results were validated numerically with the finite element method. From overall results, it was observed that the AlCrN, TiN, and AlTiN coating thicknesses have a small effect on the resonant frequencies, but a good damping effect. The resonant response of the turbocharger shaft at resonant frequencies was suppressed remarkably by the AlCrN and AlTiN coatings, especially those having a thickness of 6 and 4 µm.

Design & Development of Vortex Cooling System

Abstract: Possibilities for integration of vortex tube with automotive radiator for more effective cooling of automotive engine is the aim of the overview. An automotive radiator/heat exchanger is a device which helps maintain the working temperature of the engine. The vortex tube is a device which provides low temperature and high temperature output with pressure as an input. Because of its compact design and little maintenance requirements, it is very popular in heating and cooling processes. Despite its simple geometry, the mechanism that produces the temperature separation inside the tube is complicated. In addition, thermal and kinetic energy considerations have been used to explain temperature separation. There have also been plenty of numerical analyses that confirm earlier experiments. One fact remains, however. In this study, the past investigations of the design criteria of vortex tubes were overviewed and the detailed information was presented on the design of them. Vortex tubes were classified and the type of them was described. All criteria of vortex tubes were given in detail using experimental and theoretical results from the past until now.

Corrosion characterization of engine connecting rods using fringe projection profilometry and unsupervised machine learning

The consequences associated with corrosion, a global industrial peril, cost an estimated $ 2.5 trillion annually to inspect, rectify, and prevent. In addition to significant economic losses, corrosion-induced failure of critical components in transport systems, like automobiles, may also lead to loss of human life. Hence, it is essential to eradicate corrosion in its early stages. The most vital automobile component is its engine, whose failure can cause fatal accidents. Regular quality inspection and maintenance by skilled personnel is essential to prevent this. Automating this task will address this domain’s personnel shortage while mitigating the risk of human error. To enable the performance of this task without the need for human intervention, we determine the morphological parameters affected by corrosion in automotive engine components, namely connecting rods, using fringe projection profilometry, a high-speed 3D profiling technique capable of achieving sub-millimeter accuracy. We then perform classification using k-means clustering into low, medium, and high corrosion bands, based on the parameters obtained from 3D imaging. The model was able to achieve a high accuracy of 88.57%. The accuracy was determined by considering the visual classification performed by a Material Science Expert as the ground truth.

Optimization Based on Computer Fluid Dynamics Finite Element Method Automotive Cooling Fan Structure

With the continuous improvement of vehicle comprehensive technology, the heat load generated by automotive engine systems, hydraulic systems, and other devices also increases. Therefore, improving the heat dissipation efficiency of the cooling system is a key technology that cannot be ignored in the current vehicle development process. The car cooling fan is an important component of the cooling system, and its working characteristics will directly affect the cooling effect of the engine. This article uses the finite volume method of computer fluid dynamics to optimize the structure of a heat dissipation fan, analyze and define the flow field control volume required for its numerical calculation, use structured and unstructured grids to discretize the internal flow field region, select pressure inlet and pressure outlet boundary conditions, and simulate and analyze the fluid flow in the radiator based on fluid dynamics theory calculations. The orthogonal experimental method was used to analyze various performance indicators during the experimental process. The results showed that the comprehensive performance of the No. 3 optimized cooling fan was the best, with a 10.45% increase in static pressure efficiency, a 14.03% increase in dynamic pressure efficiency, and an 11.26% increase in maximum flow velocity. The optimized fan flow field streamline became more full and uniform, significantly improving the fluid dynamics performance of the air in the cooling system.

Optimization and prediction of a novel preignition in hydrogen direct injection engines through experimentation and the Random forest algorithms

The potential use of hydrogen in automotive internal combustion engines could aid in the energy transition and contribute to achieving carbon neutrality. This paper has investigated the impact of operating parameters boundary for a novel preignition event on a 2.0L hydrogen direct injection (HDI) engine to address the challenge of abnormal combustion limiting the application of HDI engines. The identified characteristics of the event and its potential harm to the engine has been summarized. Experiments have shown that the novel preignition event predominantly occurred mainly during 170−80°CA BTDC, hence the name PEMC (preignition in the early/mid compression stroke) event, and caused a surge in cylinder pressure. In 77.2 % of the selected cases, the PEMC events resulted in increased NOx emissions. In 93.1 % and 91.5 % of the cases, there was a decrease in brake power and brake thermal efficiency, respectively. Unlike the low speed, high load preignition of gasoline engines, PEMC events were more likely to occur in the torque range of 70–100 Nm and could be monitored in a lean mixture environment with λ = 1.5–3.3. PEMC events were found in the interval of 180−320° CA BTDC at injection timing and were most intense at 240−250° CA BTDC. To prevent PEMC events completely, it is recommended to delay the injection timing beyond 180° CA BTDC. The paper has employed a model based on experimental data and Random Forest algorithms to predict PEMC events. The model demonstrated an accuracy of 98.76 % and 97.69 % for the training and test data, respectively. It has been effective in predicting the occurrence of PEMC events under various operating conditions. The paper has offered an alternative solution for the novel preignition in HDI engines.

Teaching Reform and Practice of Ideological and Political Education in the Course of Automotive Engine Principles

The course of automobile engine principle is the foundation of vehicle professional learning. The professional knowledge and innovative value contained in the course is an effective carrier to realize moral education.This paper puts forward the implementation plan of "one center and two main lines", which is centered on promoting morality and cultivating people.Four modules, "Engine performance and cycle", "Engine ventilation", "engine fuel and combustion", "Engine characteristics and car matching", are taken as the main line of knowledge teaching."socialist core values, feelings for the family and the country, craftsman spirit, innovative thinking" as the main line of ideological and political education.At the same time, based on the network teaching platform, the whole process of before-class, in-class and after-class teaching is realized.

FEA-Based Camshaft Design and Analysis on a Range of Heat-Treated Materials

Camshafts play a critical role in internal combustion engines, dictating the timing and duration of valve opening and closing events. To ensure optimal engine performance and longevity, camshaft design must balance factors such as strength, durability, and weight. Finite Element Analysis (FEA) offers a powerful tool for evaluating camshaft designs under varying operating conditions. This paper presents a comprehensive study on the design and analysis of camshafts using FEA, focusing on the influence of different heat-treated materials. The study begins with an overview of material selection criteria for camshaft applications, considering factors such as strength, fatigue resistance, and wear characteristics. Various materials high-performance alloys are investigated for their suitability and performance enhancements through heat treatment processes such as carburizing, quenching, and tempering. A detailed 3D CAD model of the camshaft geometry is developed, capturing key features such as lobes, journals, and bearings. Finite element meshing techniques are employed to ensure accurate representation of the geometry and precise stress analysis. Boundary conditions are defined to simulate realistic operating conditions, including forces exerted by cam followers and valve springs. Material properties are assigned to finite elements based on the selected materials and heat treatment parameters. Static and dynamic FEA analyses are conducted to evaluate stress distribution, deformation, fatigue life, and natural frequencies of the camshaft under varying load scenarios. The results of the FEA analyses are used to optimize the camshaft design iteratively, considering factors such as weight reduction, performance enhancement, and durability improvement. Validation of FEA results is performed through physical testing and comparison with empirical data. Overall, this paper provides valuable insights into the design and analysis of camshafts using FEA, highlighting the importance of material selection and heat treatment processes in optimizing camshaft performance and reliability in automotive engine applications. Key Words: Design, Analysis, geartrain, idler gear, FEA, reciprocating motion, Solid works, CAD, ANSYS, efficiency, IC engines, camshaft.

Exploring the multifarious blend ratios of waste fried edible oil biodiesel/diesel/low carbon methanol in an automotive engine: An approach towards fuel characterization, experimental, and multicriteria decision making method

AbstractA low‐cost, high‐performance alternative fuel to traditional fossil fuels is required due to rising energy demand, fossil fuel depletion, and rising prices. In this case, one of the green fuels could be synthesized using transesterification from waste‐fried edible oil (WFEO). The current study deals with neat diesel (D100) and waste‐fried edible oil biodiesel (B100) as the baseline fuels. By volume, a binary blend of 50% diesel and 50% WFEO biodiesel was prepared. The biodiesel/methanol/diesel mixture was considered a ternary blend under two different ternary ratios, such as B40M10D50 and B30M20D50, respectively. The fuel characterization and the rheological study were performed for all the fuel blends as per the ASTM standards. According to engine experimental results, the B30M20D50 blend has 25.42% higher brake thermal efficiency (BTE) than B100 but 3.4% lower than D100 at full load due to the higher methanol percentage. When compared with D100, adding 20% methanol to the ternary blend reduced brake‐specific fuel consumption (BSFC) by 33.34%. Both ternary blends increased NOx emissions by 27.38% and 22.97% compared to D100 but decreased them by 14.23% and 18.68% compared to B100. Both ternary blends produced 0.4 and 0.36 kg/kWh at lower loads, while the D100 and B100 produced 0.46 and 0.42 kg/kWh. Finally, the entropy‐weighted technique for order preference by similarity to the ideal solution (TOPSIS) multi‐criteria decision‐making method was used to determine the best blend for engine performance and emissions. The entropy‐weighted TOPSIS technique likewise found that a B30M20D50 ternary blend with 75% loading had the lowest emissions and best performance.

Method for expert evaluation of the technical con-dition of the cylinder-piston group of automotive engines after hydrolock

Problem: The study examines the thermogasdynamic process within an internal combustion engine cylinder during cold cranking mode while measuring compression. Analysis of various models and comparison of known data revealed unresolved challenges in constructing mathematical models of the engine operating cycle. The vast majority of practical data and recommendations for compression measurement in a cylinder are based on empirical knowledge, numerous experiments, and tests. Consequently, there arises a need for computational models of the compression measurement process and their theoretical justification, particularly in cases where engine damage occurs during hydrolock in a cylinder. Methodology. To address the identified issues, a mathematical model of the thermogasdynamic process within the cylinder during cold cranking while measuring compression was developed. Originality. Unlike existing models, this model describes the processes in the cylinder step by step, considering the real nature of intake-exhaust processes, air leakage through part interfaces, and heat exchange with the walls. Through modeling, the main patterns of compression changes depending on the modes and the nature of damage to associated parts of the valve mechanism and the cylinder-piston group were identified, including deformation of the connecting rod during hydraulic lock due to liquid entering the cylinder. Practical value. Based on the study results, it was concluded that the model's properties make it effectively applicable in diagnosing and monitoring the technical condition of automotive engines during operation.

Enhancement of combustion, performance and emission characteristics of diesel engines fuelled with jatropha-karanja biodiesel using EGM and TGME as additive

The oxygenated additives can improve the physical properties of biodiesel blends to achieve enhanced characteristics of a diesel engine. The present work has investigated ethylene glycol monoacetate (EGM) and tri-ethylene glycol mono-methyl ether (TGME) as potential additives for the jatropha-karanja dual blended biodiesel for improved characteristics of diesel engines. The experiments have been conducted with a single cylinder four stroke diesel engine operating at constant speed of 1500 rpm. The performance, emission and combustion parameters of the engine were investigated with pure diesel, jatropha-karanja dual blended biodiesel having 20 % of methyl ester and the biodiesel added with 2, 4, and 6 % of both the additives respectively. The doping of additives improved the brake thermal efficiency by 4.1 and 4.7 % with brake specific fuel consumption dropped by 0.18 and 0.2 kg/kWh. The additives reduced the hydrocarbon emission by 29.8 % and carbon monoxide by 40 % with a slight increase in NOx emission by 5.2 %. The cylinder pressure attained value near to pure diesel while the heat release rate increased by 12.6 % indicating proper fuel combustion inside the engine cylinder. Thus, the oxygenated additives can suitably be adopted as performance improvers in biodiesel fuels for automotive engines.

Bidirectional active vibration control of two-dimensional structure inspired by automotive engine mounting system

Bidirectional active vibration control of two-dimensional structure inspired by automotive engine mounting system