Efficiency Of Internal Combustion Engines Research Articles

Kinetic study of the combustion process in internal combustion engines: A new methodological approach employing an artificial neural network

The comprehension of combustion mechanisms enables supervision of reaction rates. By adjusting factors such as heat transfer rates, combustion duration, self-ignition propensity, ignition delay and laminar flame speeds, it is possible to minimize emissions and enhance fuel conversion efficiency in internal combustion engines (ICE). The present study aims to develop and explore a methodology employing an Artificial Neural Network that uses Mass Burned Fraction data as a function of crankshaft angular position to determine combustion kinetics in ICE. The Artificial Neural Network was programmed in this work as a home-made code and produced accurate results. The kinetic triplet consisting of Activation Energy (Ea), Frequency Factor (A) and Reaction Model throughout the combustion process was determined to explore the combustion characteristics of different gasoline formulations and ICE operation conditions. The experimental data were obtained in a Single Cylinder Research Engine (SCRE) operating with gasoline formulations commercialized in Brazil. The methodology determines the kinetics of combustion along the process and recovers the values of Ea and A without resorting to mechanisms that describe each reaction individually, describing, instead, the global contribution of physical models. Because the kinetic models activate the neurons in the hidden layer, they accurately reproduce the experimental Mass Burned Fraction data and bring physical information to the network about the combustion process. The kinetic study showed that the samples with higher values of Ea also had higher ignition delay. The rate constant was also related to the consumption and combustion efficiency during the combustion process, i.e., the fuel with a higher rate constant presents greater combustion efficiency and smaller consumption.

Parametric study of combustion characteristics of diesel/methanol dual fuel engine using global sensitivity analysis and multi-objective optimization

The pursuit of clean and efficient internal combustion engine power necessitates the substitution of fossil fuels with methanol and the adoption of advanced combustion strategies. This study examines the combustion and emission characteristics of methanol/diesel dual-fuel compression ignition engines. To understand the intricate interplay between critical parameters and engine performance, the global sensitivity analysis (GSA) method is employed, utilizing Sobol sensitivity as the quantitative metric. The investigated parameters include methanol substitution rate, diesel injection parameters, and five thermodynamics parameters concerning in-cylinder conditions. A validated computational fluid dynamics (CFD) model, coupled with a chemical kinetic mechanism, is developed to predict the combustion behavior of the dual-fuel engine accurately. This predictive capability forms the basis for utilizing the tree-based process optimization (TPOT) algorithm. By implementing TPOT, a significant reduction in the mean square error (MSE) of the predicted characteristics model is achieved, averaging a decrease of 73.59 %. Subsequently, a multi-objective optimization is conducted, exploring the impact of varying target weights on the optimal outcomes. Results show the initial pressure significantly impacts the engine's economy, power and emission characteristics, and NOx formation should be carefully considered in the combustion optimization of dual-fuel engines.

The effect of the design angle of the turbine nozzle outlet of the piston engine boost system on its effectiveness

The article is devoted to the actual problem of insufficient energy efficiency of combined internal combustion engines. One of the directions of its solution, which became the goal of this work, is a reasonable choice of the optimal value of the design angle of installation of nozzles in a radial-axial turbine, taking into account both its effective power and the coefficient of completeness of using the supplied pulse energy. The authors applied a closed-loop model of the combined engine, embedded in a new calculation method, which was divided into conditional blocks. In the first block, the method of indefinite Lagrange multipliers calculates the optimal values of the turbine elements in which the gas moves. In the second block, for a preliminary assessment of the calculated geometrical parameters of the flow path, the turbine characteristics are calculated: an assumption is made about the one-dimensionality and quasi-stationary flow. For calculations, a method for calculating the parameters of a stage at an average radius was used, supplemented by a semi-empirical method for calculating gas energy losses during the movement of the latter from the turbine inlet to the outlet section. In the third block, the efficiency of the turbine was estimated when working together with a piston engine by using a closed model for it. This made it possible to objectively evaluate such characteristics of the turbine as efficiency and power, which are functionally related to the pressure pulse in the exhaust tract, which will make it possible to predict the operational characteristics of the turbine operating in conjunction with the combined engine.

CRITERIA FOR ASSESSING THE EFFECTIVENESS OF TRANSPORT POWER PLANTS DECARBONISATION IN ACCORDANCE WITH IMPLEMENTATION OF THE SUSTAINABLE DEVELOPMENT CONCEPT

The directions of restoration and further development of the energy sector in Ukraine are considered in accordance with power plants with internal combustion engines, taking into account the widespread implementation of the Sustainable Development concept, which allows solving existing modern social, economic and environmental problems. For Ukraine, taking into account the economic opportunities and selected priorities for the chosen path of development, it is necessary at this time to choose gradual and specific directions to implement the Sustainable Development concept. The most priority areas of practical implementation of the concept are determined and it is indicated that the effectiveness of this implementation is associated with the development of the industry on the basis of the fourth and fifth industrial revolutions (Industry 4.0 and Industry 5.0). One of the main tasks in solving the problems of the concept is to ensure the environmental component. Notwithstanding the noted progress in improving the environmental efficiency of internal combustion engines, further attention needs to be paid to the task of spreading the introduction of “green energy”, i.e. decarbonisation – reducing greenhouse gas emissions into the environment (CO2). The issue of decarbonisation in the future should be given the greatest attention both in the development and in the manufacture and operation of engines. It is shown that the assessment of the impact of CO2 emitted with the exhaust gases of internal combustion engines into the environment is carried out taking into account the model of operation of engines and the justification of the introduced adjustments. A new criterion is proposed, which is called: “ICE criterion of environmental thermal pollution”, which is proposed for use in studies to assess the effectiveness of the implementation of decarbonisation strategies in all modes of transport at implementation of the Sustainable Development concept in global transport power plants. A method for determining the efficiency of physical and chemical processes of mixture formation and combustion in internal combustion engine cylinders is proposed when using hybrid fuel with “green hydrogen” as its component, which allows determining the dependence of hydrogen influence on the level of engines effective performance and formation of harmful emissions in exhaust gases.

Valves materials for internal combustion engines

The main strategy for improving the efficiency of internal combustion engines is to increase the cylinder pressure, which inevitably leads to increased mechanical and thermal stress on key engine components, including the intake and exhaust valves. However, traditional materials used for engine valves today are being pushed to their limits. Thus, increasing the efficiency of the next generation internal combustion engines requires the development of new valve materials with a higher set of performance properties at elevated temperatures. The article discusses the operating conditions of engine valves and the requirements for valve materials. A comparative analysis of traditional Russian and foreign valve materials that are widely used today (martensitic and austenitic steels, nickel-based alloys) has been performed. It is noted that Russian standards for valve materials contain recommendations for the use of certain steels for engine valves, which have long lost their market positions abroad due to their inherent shortcomings. On the other hand, some foreign materials specially developed for exhaust valves of diesel engines are not produced by Russian industry. A review of new generation valve materials developed by leading foreign companies in this field to replace expensive nickel-based alloys was carried out. It is noted that the development of new domestic cost-effective valve materials capable of operating under conditions of higher temperatures and pressures in more aggressive environments is an important scientific and technical problem, the solution of which is necessary for the accelerated development of the Russian engine industry

Tribological properties under dry and lubricated sliding conditions of TiSiN and AlTiCrN coatings deposited on gray cast iron

In internal combustion engines, the majority of friction losses and wear occur between the cylinder liners and piston rings. Hard coatings applied to cylinder liners can increase the efficiency of internal combustion engines by improving tribological properties. The gray cast iron cylinder liner was coated with TiSiN and AlTiCrN employing the cathodic arc deposition process. The coatings were examined using nanoindentation tests, scratch tests, an optical profilometer, a scanning electron microscope, an X-ray diffractometer, and energy dispersive analysis to assess their hardness, adhesion, and structural characteristics. The reciprocating test was carried out to assess the coatings' wear and friction characteristics under lubricated and dry sliding with a ball at varying normal loads. The hardness of the TiSiN and AlTiCrN coatings was 45 GPa and 18 GPa, respectively. The cohesion strength, adhesion strength, and crack propagation resistance of AlTiCrN coating were approximately 2, 1.3 and 2.5 times higher than those of TiSiN coating, respectively. Both coatings exhibited remarkable wear performance at high normal loads. Under dry sliding conditions at 25 N normal load, the wear rate of AlTiCrN and TiSiN coatings were nearly 33 and 20 times, respectively, lower than the uncoated substrate. Under dry sliding conditions, the TiSiN coating exhibited the lowest wear rate at low normal loads (5 N and 15 N), while the AlTiCrN coating performed best at high normal loads (25 N). In lubricated sliding conditions, the AlTiCrN coating consistently showed the lowest wear rate across all normal loads.

A research-inducing environment to technology using friction modifier for motor gasoline fuel

The share of gasoline with improved properties reaches up to 30 % of the total production of gasoline in the world. The main component of the additive packages for these fuels is a detergent additive. However, to ensure significant environmental, economic and power effects, additional substances that modify the surface of fuel system elements and reduce friction losses are required. These substances are known as friction modifiers. In recent years, there has been a notable increase in their importance due to the tightening requirements for the efficiency of internal combustion engines (ICEs) and the increased share of gasoline engines with direct fuel injection. The current research presents the results of a systematic analysis of existing materials in the field of development and functional properties of friction modifiers. The objective is to determine the magnitude of their real impact on fuel performance. This includes the ability to increase the efficiency of ICE and reduce its fuel consumption, thereby reducing the carbon footprint. Furthermore, the most common types of friction modifiers in commercial additives from various manufacturers are presented, and existing approaches to the mechanism of action of these components are studied in order to identify the most effective additive structure.

Comparison Of A Molecularly-Controlled Combustion Engine To A DISI Engine

In addition to the increased use of electromobility, significant improvements in the efficiency of internal combustion engines (ICE) to achieve a considerable reduction of emissions is crucial to advance the transition towards a sustainable transport sector. One approach to increase the efficiency of combustion engines is active pre-chamber ignited engines (Molecularly Controlled Combustion Engines, MCC). The traditional spark ignition is replaced by a chamber that ignites a secondary fuel. The burning fuel is emitted from the pre-chamber via multiple holes, igniting the fuel air mixture in the main combustion chamber. To eject the flame jets tangentially to the pent roof, the pre-chamber protrudes into the main chamber in the center of the main chamber’s pent roof. This particular geometry of an MCCengine, however, alters the flow field inside MCC-engines. To facilitate future developments around MCC-engines and to understand the interactions of the flow field with the pre-chamber, a Stereo Particle-Image Velocimetry (SPIV) study is conducted in an optically accessible MCC-engine model. Previous velocity field data, which were acquired using a Direct Injection Spark Ignition (DISI) engine configuration at the same operating point as the MCC-engine, are compared to those of the MCC-engine. Phase-averaged velocity field data of both engines acquired during the intake stroke are compared based on their in-plane velocity fields and the in-plane vorticity. The two engine configurations show significantly different magnitudes of velocity in their combustion chamber flow field. In the MCC-engine, a downwash flow component can be attributed to flow deflection caused by the pre-chamber protruding from the engine’s pent roof. One important flow feature of ICE, the tumble vortex, is analyzed for both engine configurations. An increased absolute vorticity and a different temporal development of the tumble vorticity is noted for the MCC-engine. The tumble flap, an engine component that influences the intake flow distribution, is considered a main contributor to the difference in flow velocity and tumble vorticity.

Constructing a Skeletal Iso-Propanol–Butanol–Ethanol (IBE)–Diesel Mechanism Using the Decoupling Method

In recent years, biofuels have gained considerable prominence in response to growing concerns about resource scarcity and environmental pollution. Previous investigations have revealed that the appropriate blending of iso-propanol–butanol–ethanol (IBE) into diesel significantly improves both the c combustion efficiency and emission performance of internal combustion engines (ICEs). However, the combustion mechanism of IBE–diesel for the numerical studies of engines has not reached maturity. In this study, a skeletal IBE–diesel multi-component mechanism, comprising 157 species and 603 reactions, was constructed using the decoupling method. It was formulated by amalgamating the reduced fuel-related sub-mechanisms derived from diesel surrogates (n-dodecane, iso-cetane, iso-octane, toluene, and decalin) and n-butanol, along with the detailed core sub-mechanisms of C1, C2, C3, CO, and H2. The constructed mechanism is capable of better matching the physical and chemical properties of actual diesel fuel. Extensive validation, including ignition delay, laminar flame speed, a premixed flame species profile, and engine experimental data, confirms the reliability of the mechanism in engine numerical studies. Subsequent investigations reveal that as the IBE blend ratio and EGR rate increase, the ignition delay exhibits an increase, while the combustion duration experiences a decrease. Blending IBE into diesel, along with a specific EGR rate, proves effective in simultaneously reducing NOx and soot emissions.

Making sense of life cycle assessment results of electrified vehicles

Battery electric vehicles and plug-in hybrid electric vehicles can have life-cycle carbon dioxide emissions that can be close, within 5 % of each other, or very different depending on the efficiencies of the powertrain, relative contributions of battery and combustion engine to the traction power, and source of electricity. Life cycle assessments can provide insight into the variability in carbon dioxide emissions, but they are time consuming. In this work a simplified model that can explain the carbon dioxide emissions during the well-to-wheels portion of the life cycle is developed. The robustness of the simplified model is evaluated by varying parameters and comparing its results with those from the life cycle assessment. Assumptions must be made to conduct the assessment. The assumptions include the efficiencies of the internal combustion engine, the battery, the drivetrain, and regenerative braking, and the relative contribution of the battery to traction power in the plug-in hybrid electric vehicle. Renewable and non-renewable sources of generating electricity are considered. It is concluded that a plug-in hybrid electric vehicle with the same parameters as the battery electric vehicle can potentially be lower emitting only when the emissions factor of the electricity generation and the internal combustion engine efficiency are high. For low carbon intensity electricity generation, the plug-in vehicle emits more carbon dioxide than the battery electric vehicle for the range of internal combustion engine efficiencies considered.

Stress mitigation of a thermal engine head block using the bioinspired BGM-FEM method

Structural optimization plays a pivotal role in the design and development of engine heads, as it directly affects the performance, efficiency, and durability of internal combustion engines. In this paper, we propose a novel approach for the thermo-structural optimization of the internal surfaces of the engine heads, using the Biological Growth Method (BGM). The BGM is a bio-inspired technique that mimics the growth patterns observed in some biological organisms, able to achieve superior structural efficiency thus generating optimal designs. The effectiveness of the BGM methodology, coupled with mesh morphing techniques based on Radial Basis Functions (RBF), is in this work demonstrated for several districts, effectively reducing material usage and enhancing structural performance.

Performance and Emission Analysis of Ethanol-Petrol Blends in Single-Cylinder Engines: A Sustainability Perspective

This study investigates the blending of ethanol and petrol in the Indian subcontinent, addressing the urgent need for sustainable fuel alternatives amid rising energy demands and environmental concerns. Ethanol, as a renewable biofuel, presents a viable option for enhancing the efficiency of internal combustion engines while reducing harmful emissions. Given the significant air pollution issues prevalent in urban areas of India, optimizing fuel blends can substantially improve engine performance and contribute to cleaner air. The primary objectives of this research include analyzing the impact of different ethanol-petrol blends on the performance of a single-cylinder petrol engine, assessing key performance metrics such as brake power, Indicated Mean Effective Pressure (IMEP), Brake Mean Effective Pressure (BMEP), and Brake Thermal Efficiency (BTHE). Emission analysis was conducted to measure hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO₂), oxygen (O₂), and nitrogen oxides (NOₓ) across various blends, quantifying the environmental impact of each. Grey Relation Analysis (GRA) was employed to rank the fuel blends based on their performance and emissions, helping identify the most effective blend for optimal engine operation. Additionally, the sustainability of ethanol blending as an alternative fuel solution in the Indian automotive sector was assessed. The study recorded key performance indicators and emissions using standardized techniques, with GRA calculating Grey relational coefficients to measure the degree of similarity between observed data and desired outcomes. This approach facilitated the ranking of blends, ultimately identifying the optimal ethanol-petrol blend. The findings revealed significant variations in both performance and emissions across different blends, indicating that ethanol blending holds substantial promise as a sustainable solution for the Indian automotive sector. These insights align with recent studies on the benefits of biofuels in enhancing engine performance and reducing emissions, providing valuable guidance for optimizing ethanol-petrol blends to improve sustainability in energy consumption.

The effects of ammonia addition on the emission and performance characteristics of a diesel engine with variable compression ratio and injection timing

Ammonia, future of the carbonless marine fuel, presents significant potential in achieving zero-emission targets within maritime transportation. In this context, this study explores the use of an ammonia/diesel fuel mixture in a diesel engine, employing both experimental and numerical methods. We focus on the impact of injection timing and compression ratio to optimize the engine while using ammonia/diesel mixture in terms of both engine performance and exhaust emissions. The results show a decrease in engine power with an increasing content of ammonia, reaching the lowest power of 4.53 kW at 60% ammonia content. On the other hand, the increase in compression ratio generally enhances engine power. Thermal efficiency shows an increase up to 40% ammonia content, followed by a decline. CO2 emissions significantly reduce with an increase in ammonia content, reaching the lowest level, especially at 60% ammonia content. NO emissions rise with increasing ammonia content up to 40%. Furthermore, increasing the compression ratio reduces CO2 emissions and contributes to an increase in NOx emissions. These findings have assessed the potential usage of ammonia-diesel fuel mixture with regards to environmental impacts and energy efficiency in internal combustion engines.

On convection vive in mixing-controlled combustion with thermal barrier coatings

Thermal barrier coatings (TBCs) could improve the efficiency of internal combustion engines by reducing heat losses. TBC modeling has demonstrated efficiency gains at all loads in compression ignition, including in gasoline compression ignition (GCI). However, after GCI testing of 13 coated pistons of various materials, thicknesses, and surface preparations in this work, a clear trend was observed: TBCs result in an efficiency gain at 6 bar IMEPn (low load) and an efficiency penalty at 15 bar IMEPn (high load). This can be explained by “convective vive”, which was originally presented by Woschni for engines with TBCs. Convection vive refers to a reduction in the quench distance of a reacting flame when the quenching surface temperature is elevated, resulting in an increased heat transfer coefficient and heat transfer rate despite the lower temperature difference between the gas and the wall. Although this work is unable to provide direct experimental evidence for convection vive, several experiments were performed to rule out alternate theories including differences in heat release rate, radiation heat transfer, combustion chamber deposits, and surface catalytic effects. Experiments also showed that at 6 bar IMEPn, injection pressure did not impact the performance of the TBC compared to the metal baseline, but at 15 bar IMEPn, the efficiency penalty increased with rail pressure. These results provide indirect evidence of convection vive: as the surface temperature of the TBC increases with load past a threshold, the quench distance decreases to the point where exothermic reactions can occur in the boundary layer, which raises the convective heat transfer coefficient. This implies that in mixing controlled combustion systems, the TBC should not be present on combustion chamber surfaces that experience high fuel-wall interaction during combustion.

Efficiency Evaluation of Using Water-Fuel Emulsion as Fuel for Automobiles

Road transport is the main consumer of petroleum fuel as well as a source of toxic substances. Therefore, reducing fuel consumption and emissions of harmful substances in road transport is one of the most important problems facing modern engine construction. One of the ways to solve this problem is through the use of mixed fuels, including water-fuel emulsions. Water-fuel emulsion is a promising alternative fuel that could fulfill such requests in that it can improve the combustion efficiency of internal combustion engines and reduce harmful exhaust emissions, especially nitrogen oxide (NOx) and particulate matter (PM). Up to now, there have been many studies on water-fuel emulsions, especially on performance, emissions and micro-explosion phenomena. Using water-fuel emulsion as fuel for ships worldwide was studied and applied to the 80-ies of the last century, but using it for automobiles is still limited by the emulsion stability and economic difficulties to calibrate engine parameters for a new fuel. This article provides an overview of the mechanism and performance operating cycle of internal combustion engines using water-fuel emulsions and the efficiency, economy, and environmental friendliness of this fuel type for automobiles. Hence, conclusions are drawn about the possibility and effectiveness of using emulsions as fuel for automobiles, especially under conditions in Vietnam.

Swirl-induced motion prediction with physics-guided machine learning utilizing spatiotemporal flow field structure

PurposeHigher energy conversion efficiency of internal combustion engine can be achieved with optimal control of unsteady in-cylinder flow fields inside a direct-injection (DI) engine. However, it remains a daunting task to predict the nonlinear and transient in-cylinder flow motion because they are highly complex which change both in space and time. Recently, machine learning methods have demonstrated great promises to infer relatively simple temporal flow field development. This paper aims to feature a physics-guided machine learning approach to realize high accuracy and generalization prediction for complex swirl-induced flow field motions.Design/methodology/approachTo achieve high-fidelity time-series prediction of unsteady engine flow fields, this work features an automated machine learning framework with the following objectives: (1) The spatiotemporal physical constraint of the flow field structure is transferred to machine learning structure. (2) The ML inputs and targets are efficiently designed that ensure high model convergence with limited sets of experiments. (3) The prediction results are optimized by ensemble learning mechanism within the automated machine learning framework.FindingsThe proposed data-driven framework is proven effective in different time periods and different extent of unsteadiness of the flow dynamics, and the predicted flow fields are highly similar to the target field under various complex flow patterns. Among the described framework designs, the utilization of spatial flow field structure is the featured improvement to the time-series flow field prediction process.Originality/valueThe proposed flow field prediction framework could be generalized to different crank angle periods, cycles and swirl ratio conditions, which could greatly promote real-time flow control and reduce experiments on in-cylinder flow field measurement and diagnostics.

Checking the Mechanisms of Internal Combustion Engines for the Presence of Parasitic Forces Using a New Methodology

This article presents the results of a study of internal combustion engines equipped with a crank mechanism according to the efficiency criterion using a new method for determining the operating efficiency of machines and engines. The study revealed the presence of parasitic forces in internal combustion engines equipped with a crank mechanism. The occurrence of parasitic forces present in internal combustion engines and the law of their dependence on the movement of the piston have been studied. As well as the negative impact of parasitic forces on engine efficiency. This article presents the main results of the study. As a result of the research, it was revealed that when converting the thermal energy generated in the combustion chamber of internal combustion engines equipped with a crank mechanism into mechanical work, more than 30% of the energy of the pressure force is spent on parasitic forces. The influence of the mechanical friction force (friction of the plain bearings) with the crankshaft on the effective torque was also studied. Thus, the inefficiency of internal combustion engines equipped with a crank mechanism has been theoretically and practically proven. Finally, recommendations are given for eliminating parasitic forces when designing new internal combustion engines. It is proposed to equip new internal combustion engines with mechanisms without parasitic forces. Equipping internal combustion engines with a mechanism that does not contain parasitic forces (that is, equipping them with more efficient mechanisms) significantly increases the possibility of efficient use of the thermal energy of the fuel introduced into the combustion chamber in internal combustion engines. Consequently, this increases the engine efficiency by 130%. or more. For internal combustion engines, a new mechanism is recommended that eliminates the loss of force and allows the use of rolling bearings. This feature of the new mechanism makes it possible to increase the efficiency of internal combustion engines by another 4-6%. From previous studies it is known that the efficiency of a rolling bearing relative to a plain bearing is more than 2-3 times.

Enhancing Fuel Efficiency of Internal Combustion Engine through the Application of Nanostructured Aluminium Alloy in Pistons

‌The automobile and motorsport industires are under immense pressure due to emission laws to reduce fuel consumption and alleviate the effects of global warming. This experimental study compared the performance of internal combustion engine pistons made of a newly developed nanostructured aluminium alloy (RSA-612) and conventional aluminium alloy 2618. The new alloy is expected to reduce piston mass which will reduce piston assembly frictional losses and lead to reduced fuel consumption. The new alloy has lower density and higher strength at elevated temperatures than conventional aluminum alloys, and the final machined piston was 13.5% lighter than the original piston. The limited engine testing carried out in this study showed that the new piston produced enhanced performance in certain engine operating conditions, whilst performing similarly or slightly worse in others. Further testing with the new piston is advised to assess engine performance across wider engine running envelope.

Fabrication and characterization of thermal barrier coatings for internal combustion engines via suspension plasma spray with high solid loading

Suspension plasma spraying (SPS) technique producing thermal barrier coatings (TBCs) with high porosity and good thermal shock resistance has great potential to improve the thermal efficiency of internal combustion (IC) engines. However, its wide usage is limited by the immature fabrication technology and low spraying efficiency. Therefore, this study optimized the SPS process with high solid loading and characterized the properties of the coating to obtain TBCs suitable for IC engines. Suspension composition optimization revealed that polyethylenimide (PEI) has the best dispersion effect, and a suspension with high solid loading of 35 wt% was obtained. Furthermore, the effects of the spraying distance, feeding speed and spraying power on the coating microstructure were investigated, and the porosity and thermal shock resistance of the coatings were characterized to determine the optimal spraying process. Thermal shock failure of SPS coatings primarily arises from the propagation of horizontal cracks originating from vertical intercolumn cracks. The SPS coating with a feathery columnar structure has the best thermal shock resistance. By optimizing the spraying process, a coating with porosity up to 24.16 %, bonding strength of 41.69 MPa, and good thermal shock resistance is successfully achieved.

A REVIEW OF EGR APPLICATION FOR AUTOMOTIVE INDUSTRY

Exhaust gas recirculation (EGR) has been widely adopted as an effective strategy to reduce harmful emissions and improve fuel efficiency in internal combustion engines. This review paper aims to provide a comprehensive analysis of the utilization of EGR in various types of internal combustion engines. The review covers the principles of EGR operation, its effects on engine performance, emission reduction capabilities, challenges, and prospects. By evaluating the existing literature and research findings, this paper seeks to offer insights into the potential of EGR as a crucial technology for sustainable and environmentally friendly auto-motive propulsion systems.