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Internal combustion engines (ICEs) fuelled with hydrogen can play a major role in the short-term future transportation sector since they abate all criteria pollutants at engine-out reducing tailpipe CO2 emissions to near-zero levels. However, optimizing hydrogen ICEs is a challenging task that can be addressed through the development of a robust simulation tool capable to predict the H2 combustion process. In this study, a previously developed two-zone combustion model has been updated considering different laminar flame speed computations, both based on a detailed chemistry scheme: a polynomial correlation function and a tabulated approach. The predictive capabilities of the combustion model have been validated against experimental data coming from a 0.5L PFI single-cylinder engine under several operating conditions. The tabulated approach for laminar flame speed definition proved to be the best solution, leading to a combustion duration average error lower than 3 deg over a dataset containing more than 45 different operating conditions. • A predictive combustion model for hydrogen combustion was developed. • The air-hydrogen laminar flame speed calculated using detailed chemical kinetics. • Two approaches tested for implementing the laminar flame speed calculations. • Tabulated laminar flame speed provides high predictive capabilities. [ABSTRACT FROM AUTHOR]

In response to the escalating emphasis on sustainability across diverse sectors, this study addresses the imperative to combat environmental degradation through conscientious development. The primary focus is on assessing the feasibility of replacing fossil fuels with renewable alternatives in internal combustion engines (ICEs) equipped with direct fuel injection. The research employs energy and exergy analyses, coupled with economic analysis, to comprehensively evaluate the performance of fuels and blends. Applying the Lotus Engine software, computational analyses are conducted, taking into account the specific geometry of the engine. Simulations explore different λ‐factors to identify optimal performance configurations for each fuel or blend. Noteworthy outcomes reveal that blends featuring green hydrogen yield remarkable improvements, showing high torque (max. +11.5%), power (max. +14.35%), thermal efficiency (max. +3%), and exergy efficiency (max. +21.56%). These blends also demonstrate reduced operating costs (max. −10%), although with higher exergy losses, indicating areas for potential enhancement. Conversely, fuels containing ethanol show intermediate values between the blends and pure fuels. Consequently, this study effectively establishes the significance of these fuels in ICEs, supported by comprehensive energy, exergy, and economic analyses. The findings underscore the promising potential of renewable fuels as viable alternatives to fossil fuels, marking a substantial stride towards sustainable energy solutions and environmental preservation. [ABSTRACT FROM AUTHOR]

The increasing demand for vehicles is leading to a rise in pollutant emissions across the world. This decline in air quality is significantly impacting public health, with internal combustion engines being a major contributor to this concerning trend. Ever-stringent regulations demand high engine efficiency and reduced pollutant emissions. Therefore, every automobile company requires rigorous methods for accurately estimating engine emissions. The implementation of advanced technologies, including machine learning methods, has proven to be a promising solution. The present work aims to develop an artificial intelligence-based model to estimate the pollutant emissions produced by an internal combustion engine under varying operating conditions. Experimental activities have been conducted on a single-cylinder spark ignition research engine with gasoline port fuel injection under both stationary and dynamic operating conditions. This work explores different artificial intelligence architectures and compares their performance in order to determine the best approach for the presented task. These structures have been trained and tested based on data obtained from the engine control unit and fast emission analyzer. The main target is to evaluate the possibility of applying the presented artificial intelligence predictive model as an on-board virtual tool in the estimation of emissions in real driving conditions. [ABSTRACT FROM AUTHOR]

The internal combustion engine plays a very important role in many fields, and when the internal combustion engine fails, if it is not found in time, it may cause continuous damage to the internal combustion engine, and further affect the life of the entire mechanical system. To solve the above problems, this paper proposes fault detection of internal combustion engines based on a random convolutional neural network. The cylinder burst noise signal of the internal combustion engine is decomposed by a stationary wavelet, and the inclusion matrix is composed of partial decomposition coefficients. Using singular value theory, the singular value containing matrix is extracted as the characteristic of cylinder burst noise signal. The singular value is used as the input of a random convolutional neural network to train and identify faults. The AdaBound optimizer was then applied to adapt the learning rate to changes, thereby accelerating the weight update of the model. At the same time, the neurons in the structure are randomly deactivated by dropout technology to prevent complex collaborative responses to the training data, and the diagnosis results of each network model are integrated by Dempster synthesis rules. The experimental results show that the minimum mean square error of 0.00165 is achieved when there are 15 neurons in the hidden layer, and it gradually increases as the number of neurons increases. Therefore, it is determined that there should be 15 neurons in the hidden layer, and the trainLM algorithm is used. The decision factors for training, validation, cross-validation, and overall data are 0.98947, 0.98597, 0.97738, and 0.9801, respectively, all reaching the control accuracy of 0.95, which indicates that the random convolutional neural network proposed has a high accuracy for internal combustion engine fault detection. For the main bearing Y-directional force, as the gap increases, its fluctuation trend strengthens; the main bearing force changes within a small range at first, then increases sharply when the gap reaches 0.2mm, and some main bearings even experience significant impact loads. [ABSTRACT FROM AUTHOR]

Most motor vehicles have historically utilized Internal Combustion Engines powered by a fossil fuel. Despite the technological advancements in fuel-efficient engines, further improvements are required to reduce the effect of fuel costs and global warming. This study models and simulates Hybrid Electric Vehicles (HEVs) to evaluate their potential for fuel cost savings and emissions reduction compared to traditional vehicles. Using MATLAB® version R2023a Update 5 (9.14.0.2337262) Simulink version 10.7 (R2023a) and the Advanced Vehicle Simulator (ADVISOR) version 2003-00-r0116, the research examines Series and Parallel HEV configurations. The simulation explores various battery configurations, engine capacities, and power unit models to analyze their impact on energy utilization. The data, collected from the simulations, show significant fuel savings and emissions reduction with HEVs. The Parallel HEV configuration consistently saves fuel with fewer battery modules, while the Series HEV configuration performs better but requires more modules to maintain the system's State of Charge. [ABSTRACT FROM AUTHOR]

A notable trend in the modern automotive market is the increased interest in hybrid cars. Hybrid cars combine a standard internal combustion engine with an electric motor solution. Research into increasing the energy efficiency of a conventional unit while meeting increasingly stringent exhaust emission standards is becoming a key postulate in this matter. This article discusses an analysis of modifying the fuel used by hybrid vehicles using the example of a selected drive unit equipped with a spark-ignition engine. This effect was tested after the Eco Fuel Shot liquid catalyst was added to the fuel. The research process was carried out in two stages, as follows: in road conditions using the Dynomet road dynamometer; and on the V-tech VT4/B2 chassis dynamometer. Tests were carried out to replicate road tests with a catalytic additive in the fuel. A mathematical model was created and the following energy efficiency parameters of the hybrid vehicle were calculated: the torque of the internal combustion engine, electric motor, and generator; the rotational speeds of the internal combustion engine, electric motor, and generator; the power of the internal combustion engine, electric motor, and generator; the equivalent fuel consumption of the electric motor and generator; the fuel consumption of the internal combustion engine, electric motor, and generator; and the mileage fuel consumption of the internal combustion engine, electric motor, and generator. The results of the tests made it possible to identify the benefits of using the tested liquid catalyst on the operation of the drive system of the analyzed hybrid vehicle. This research will be of benefit to both the demand side in the form of users of this category of vehicles, and the supply side represented by the manufacturers of power units. [ABSTRACT FROM AUTHOR]

The hydrogen internal combustion engine (H 2 -ICE) is proposed as a robust and viable solution to decarbonise the heavy-duty on- and off-road, as well as the light-duty automotive, sectors of the transportation markets and is therefore the subject of rapidly growing research interest. With the potential for engine performance improvement by controlling the internal mixture formation and avoiding combustion anomalies, hydrogen direct injection (H 2 DI) is a promising combustion mode. Furthermore, the H 2 -ICE poses an attractive proposition for original equipment manufacturers (OEMs) and their suppliers since the fundamental base engine design, components, and manufacturing processes are largely unchanged. Nevertheless, to deliver the highest thermal efficiency and zero-harm levels of tailpipe emissions, moderate adaptations are needed to the engine control, air path, fuel injection, and ignition systems. Therefore, in this article, critical design features, fuel-air mixing, combustion regimes, and exhaust after-treatment systems (EATS) for H 2 DI engines are carefully assessed. [Display omitted] • Key design aspects for achieving high efficiency and low emissions summarised. • Injection and intake ports are critical for good in-cylinder mixture formation. • Thermal management is required to mitigate abnormal combustion. • Advanced boosting system required to obtain high power density. [ABSTRACT FROM AUTHOR]

AbstractThis study focuses on developing an innovative device for isolating and managing exhaust gases from diesel locomotive engines, specifically aiming to reduce environmental impact and enhance operational safety. The study used experimental analysis, validated results using Cochrane and Fisher criteria, and conducted empirical data analysis. Study utilized an experimental stand with a 1.9-liter Volkswagen diesel engine, ZIL-130 compressor, custom exhaust gas storage system with tanks, thermometers, pressure gauges, and control valves. The study developed a mathematical model analysing input parameters and system outputs, achieving 95% accuracy, proving its reliability in representing exhaust gas dynamics of TEM2 diesel locomotives. [ABSTRACT FROM AUTHOR]

The article presents the results of testing the validity of the hypothesis about the possibility of isolating the exhaust gases of the internal combustion engine (exhaust gas source). The objective was to conduct an experimental study of the "exhaust gas source - storage tank" system. In the experimental study, the following was performed: establishment of influencing factors and output parameters; selecting the number of experiments; methods and means of measurement; conducting an experiment at the stand. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The complexity of modern powertrains with their embedded control systems has increased in the last years, due to the tightening of emission regulations. Therefore, virtual calibration and Model-in-the-Loop testing can provide a great support for their preliminary assessment, in order to reduce the experimental effort. To this purpose, highly accurate engine models are required, not only at steady-state conditions, but also in transient operation. The present paper addresses the assessment and validation of a fast-running 1-D model of a diesel engine for heavy-duty applications, focussing on the transient response. In particular, a baseline model with satisfactory accuracy at steady-state operation, but not in transient conditions, is analysed and assessed with the aim of reproducing the true dynamic response of the real engine installed at the test bench, as well as the behaviour of the embedded air-path controllers. The entire methodology for the model assessment is presented step by step, and common challenges and potential pitfalls that researchers may encounter when calibrating simulation models are discussed. Finally, the impact of the test bench layout on the engine dynamic response is also evaluated and discussed. [ABSTRACT FROM AUTHOR]

The transition to electric vehicles (EVs) will require significant changes in the automotive industry, particularly concerning its labour force. This study evaluates the impact of EVs on employment within South Africa's automotive component manufacturing sector. A system dynamics model was developed to assess the effect of EV market penetration on component manufacturing employment over time. Key drivers of employment in the conventional and the EV component industries were identified and incorporated into the model. The results indicate a negative impact of EV penetration on employment of 18.3% when considering 20.0% EV sales (EV20) in 2040. Scenario analyses highlighted the influence of individual components, battery localisation, and load shedding on labour. Tyre and wheel manufacturing was found to be the most labour impactful component in the conventional industry against electrical engines in the EV counterpart. Localising 25.0% of battery production could increase employment by 6.9% and 2.7% in the EV40 and EV20 Scenarios. Load shedding has a detrimental effect on the country's economy, assumed to reduce employment by 30.0%. However, strategic industry and policy interventions can mitigate the adverse effects of this transition. [ABSTRACT FROM AUTHOR]

Heat transfer from the walls of engine has a significant role on engine combustion, performance and emission characteristics. The study objectives to showcase the efficacy of the new model through an analysis by comparison with existing heat transfer models. New model is based on woschni model in which pressure and temperature is replaced by other fluid properties like density, thermal conductivity and dynamic viscosity. A series of experiments were conducted on a compressed natural gas internal combustion engine across varying hydrogen fractions, EGR ratios, engine speeds and different loads under stoichiometric conditions. The study demonstrates the efficacy of the proposed model by constantly achieving high prediction quality across a wide range of engine calibration coefficients by using Quasi-dimensional Combustion Model (QDCM) on MATLAB. Comparative analyses of new model with different heat transfer models were undertaken to validate the heat transfer rates with experimental results across a broad spectrum of operational conditions. It is observed that heat transfer rate is increased by increasing the engine load as 25%, 50%, 75% and 100% as 90.57J/deg, 130.12J/deg, 200.02J/deg, and 260.26J/deg with new model correspondingly. Heat transfer rate reduced by rise in engine speed with 1100 rpm, 1200 rpm, 1500 rpm and 1700 rpm is as 32.91 kW, 32.16 kW, 25.36 kW and 18.03 kW by new heat transfer model respectively. Artificial neural network (ANN) popular backpropagation algorithm is adopted to predict the heat transfer rate of HCNG engine, the five-input and one-output network structure are used. The values of correlation coefficient (R) and mean square error (MSE) were 0.99957 and 0.22667, 0.99998 and 0.010776, 0.99253 and 4.4762, 0.9961 and 1.2329, 0.99994 and 0.025108 for Woschni, New_Model, Chang, Sitkei and experimental respectively. This research work offers that ANN is a wise option for conventional modeling systems. In this way, the heat transfer rate of hydrogen-added CNG engines may be precisely predicted using ANN modeling. • Experiments were performed on the HCNG engine under a wide range of operating conditions. • The heat transfer rate analysis of different models by QDCM and compared with new model. • In new model, pressure and temperature is replaced by other fluid properties like density, thermal conductivity and dynamic viscosity. • Heat transfer rate increases by increasing the hydrogen fraction and load. • Artificial neural network (ANN) popular backpropagation algorithm is adopted to predict the heat transfer rate of HCNG engine. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Considering that the heat required for the Waste heat recovery (WHR) cycle of the engine is provided from two parts of the exhaust gas and the cooling system, the mutual influence of the WHR cycle on the engine performance is undeniable. Therefore, in this numerical study, an attempt has been made to thermodynamically evaluate the effect of the implementation of the WHR cycle on the engine efficiency. For this purpose, the 16 cylinder MTU 4000 R43L heavy diesel engine was simulated and a comparison was made between numerical and experimental results. Finally, the SRC heat recovery cycle was designed and applied in the simulated model according to the desired limits and the temperature range of the engine operation. At low speed with the application of the WHR cycle, the output net power did not drop much, but at the maximum speed and power, a power loss of about 4% is observed. At 1130 rpm, the power did not increase much. At 1600 rpm, the power increase is reduced to about 2.3%. At 1800 rpm, due to the significant increase in exhaust gas temperature, the total power value increased by about 4%.

The paper shows that the efficiency of the machine and tractor fleet is significantly influenced by operating conditions. It is known that the harsher the operating conditions, particularly those related to climate, the higher the frequency of failures, which, in turn, results in the reduced durability and efficiency of the equipment. One way to mitigate failures and power losses in the motor-transmission unit, as well as improve fuel efficiency, is by utilizing the waste heat from the internal combustion engine. This approach ensures an optimal temperature in the main units of the machinery at negative ambient temperatures. (Research purpose) The research aims to develop a technological scheme for utilizing waste heat from the internal combustion engine, specifically the heat from exhaust gases, to maintain the optimal temperature in the main units of the machine and tractor unit. (Materials and methods) The potential for using exhaust gas heat in the proposed scheme was studied and assessed using an experimental setup. The results were processed using the exergy research method. (Results and discussion) It is found that the power of the exhaust gas heat fl w at various engine operating modes provides favorable conditions for its utilization in the proposed scheme. Based on the research results, a system for maintaining a set temperature regime in the main units and trailer unit of a self-propelled machine was developed and patented. (Conclusions) The presence of significant kinetic and thermal energy in the exhaust gases enables its secondary use. A technological scheme for utilizing the heat of exhaust gases from internal combustion engines has been developed as a system for maintaining a set temperature regime in the main units and trailer unit of a self-propelled machine. The application of the developed system will maximize the utilization coefficient of the heat released during fuel combustion in the engine.

The purpose of the study is to find a technique and conduct on its basis a harmonic analysis of the torque of an internal combustion engine for the subsequent determination of resonant vibrations of the crankshaft. The method of calculating the harmonics of the engine torque is given on the example of a YaMZ-5340 diesel engine with a power of 100 kW at a crankshaft rotation speed of 2300 min-1. Based on the results of thermal and dynamic calculation of the YaMZ-5340 engine, a graph of changes in its torque is constructed and harmonics of the first and second orders are calculated. The frequencies of natural and forced vibrations of the crankshaft and its resonant critical rotation frequency are determined. The number of the torque harmonic has been determined, which, according to the frequency of forced vibrations, coincides with the frequency of natural vibrations and causes resonance. The results of the study can be applied in the design and fine-tuning of engines in order to calculate and reduce torsional vibrations.

Introduction. To ensure stable performance of transport and technological machines, constant monitoring of their technical condition is necessary. Timely diagnosis is difficult to carry out when working in remote regions, as well as when transporting goods over long distances due to the lack of closely located maintenance centers.Materials and methods. One of the solutions to the above problem is the use of a diagnostic method based on sound parameters. In particular, this method is applicable to power plants. Its advantage is the ability to quickly assess the condition of the engine mechanisms and systems on site using a portable device (without the use of large-sized and low-mobility equipment) by non-destructive testing. Thus, the research and implementation of the acoustic diagnostic method is promising and in demand today. One of the most important areas for improving power plants today is the automation of control processes for their operation based on the use of electronics and microprocessor systems. With a positive effect on the efficiency of the engine, these complex systems expand the range of its potential malfunctions. The purpose of this study was to evaluate the fundamental possibility of determining and comparing the acoustic parameters of an engine with and without violations of the operating mode in the event of failures in electronic control systems of its operation. As an example, the Ford Focus passenger car was chosen as the object of the study. A malfunction in the electronic ignition module was used as a test fault. The obtained spectral patterns of the sound radiation of the internal combustion engine (with and without violations of the operating mode) enable to determine the nature of the engine malfunction by sound parameters.Results. A frequency range at which it is possible to identify the spectral pattern of an engine with impaired operation and an engine without impaired operation was obtained. This range was 6,000-6,500 Hz, since in this segment the sound level reaches more than 40 dB.Discussions and conclusions. The conducted experiment is the initial stage of a large-scale experimental study, the result of which will serve as a starting point for the introduction of the acoustic method into the process of diagnosing electronic control systems for internal combustion engines.

The relevance of the topic of this study is due to the need to ensure reliable operation of vehicles and minimize the risks of interruptions in the operation of internal combustion engines (ICE). A common phenomenon in operation is misfiring, which negatively affects the efficiency of the ICE and can lead to emergencies that entail significant financial and temporary losses for commercial companies. The problem is the need to identify and prevent such malfunctions early. The purpose of the study is to develop and test a system for monitoring and analyzing the technical condition of the internal combustion engine through vibration measurements. Method and methodology. The work used the method of in-place diagnostics, the use of which increases efficiency of determining the technical condition of the vehicle internal combustion engine. Results. This article describes the system developed by the authors for checking the technical condition of an internal combustion engine. As a result, software to process and record vibration and timing data has been developed in MATLAB. The study of influence of defects in mechanisms and systems of internal combustion engine on uniformity of time-amplitude characteristic of vibration pulses of each individual cylinder, which occur during operation of internal combustion engine, was carried out by calculation and experimentation. As a key conclusion, it is noted that the developed system allows to quickly and non-invasively identify the idle cylinder or the one of which contribution to the rotational movement of the crankshaft is the least compared to others. The research makes it possible to provide diagnostics in a short time using available means. Scope of application of the results. the research results were tested in the conditions of a service company when diagnosing the internal combustion engines of passenger cars and trucks, and can be applied by both car repair shops and car enthusiasts.

Abstract Exhaust emissions, which count among the most common causes of premature death worldwide, can cause irreversible changes in cells, leading to their damage or degeneration. In this research, L929 line cells were observed after exposure in the BAT-CELL chamber to exhaust gases emitted from a Euro 6 compression-ignition engine. Real road traffic conditions were simulated, taking into account air resistance while driving at speeds of 50 km/h, 120 km/h and idling engine. Morphological analysis of the cells was performed using an environmental scanning electron microscope. It has been observed that diesel exhaust fumes can cause inflammation, which can induce apoptosis or leads to necrotic cell death. The impact of the vehicle exhaust gases can inhibit cell proliferation by almost three times. Moreover, a correlation has been observed between the speed of the inflammatory reaction in cells and the presence of specific hydrocarbon compounds that determine the toxicity of exhaust gases. Research has shown that the toxicity of the emitted exhaust gases has been the highest at the driving speed of 120 km/h. In order to reduce the harmful effects of exhaust emissions, ecological alternatives and the supplementation of legal provisions regarding the compounds subject to limitation are necessary.

Internal combustion engines (ICEs) are one of the significant sources of wasted energy, with approximately 65% of their input energy being wasted and dissipated into the environment. Given their wide usage globally, it is necessary to find ways to recover their waste energies, addressing this inefficiency and reducing environmental pollution. While previous studies have explored various aspects of waste energy recovery, a comparative analysis of different bottoming configurations has been lacking. In this research, an extensive review of the existing literature was conducted by an exploration of four key bottoming cycles: the steam Rankine cycle (SRC), CO2 supercritical Brayton cycle, inverse Brayton cycle (IBC), and air bottoming cycle. In addition, these four main bottoming systems are utilized for the waste energy recovery of natural gas-fired ICE with a capacity of 584 kW and an exhausted gas temperature of 493 °C. For the efficient waste heat recovery of residual exhausted gas and heat rejection stage of the main bottoming system, two thermoelectric generators are utilized. Then, the produced power in bottoming systems is sent to a proton exchange membrane electrolyzer for hydrogen production. A comprehensive 4E (energy, exergy, exergy-economic, and environmental) optimization is conducted to find the best main bottoming system for hydrogen production. Results showed that the SRC-based system has the highest exergy efficiency (21.93%), while the IBC-based system results in the lowest efficiency (13.72%), total cost rate (25.58 $/h), and unit cost of hydrogen production (59.91 $/GJ). This combined literature review and research article underscore the importance of finding an economically efficient bottoming cycle in the context of waste energy recovery and hydrogen production. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Global warming is a major environmental issue caused by the release of greenhouse gases, such as carbon dioxide into the atmosphere. Light-duty vehicles (LDVs) including passenger cars and light-duty trucks, are a significant contributor to greenhouse gas emissions. The transportation sector is responsible for approximately 23% of global CO2 emissions, with LDVs accounting for a substantial portion of these emissions. This paper aims to investigate the feasibility of zero-carbon fuels with focus on hydrogen and ammonia in spark ignition internal combustion engines for light-duty vehicles. With the increasing demand for sustainable and carbon-free mobility, alternative fuels such as hydrogen and ammonia are gaining attention as potential solutions. The properties and characteristics of these fuels and their potential for utilising them as a fuel in internal combustion engines are also reviewed. Current challenges and opportunities associated with the use of these fuels, including production, storage, and distribution, will be discussed. While there are still technical and infrastructural challenges that need to be addressed, hydrogen and ammonia have the potential to provide clean and efficient energy sources for light-duty vehicles. The development of these fuels, along with advancements in internal combustion engine technology, can help pave the way towards a carbon-free future for mobility. [ABSTRACT FROM AUTHOR]

In heat engines utilizing fuel injection, the processes of atomization and spray formation have a significant impact on the combustion process, thereby determining both efficiency and emission characteristics. Accurate prediction and control of spray formation in fuel injection systems play a key role in improving the efficiency and environmental performance of thermal engines, especially with the emergence of carbon-neutral fuels. To achieve accurate prediction of spray mixture formation, it is imperative to refine the atomization model for the liquid jet within numerical simulations. This requires a phenomenological representation of the atomization process that avoids reliance on computational constants obtained from spray experimental results. Consequently, the present study attempts to mathematically model the turbulent nozzle flow and liquid jet atomization process, leading to the development of a novel primary breakup model. The construction of the primary breakup model involves an analysis of the turbulence at the nozzle inlet. By merging this turbulence with the turbulence resulting from wall shear flow within the nozzle, the model provides insight into the internal turbulence and surface instability of the liquid jet, encompassing the turbulence spectrum. Consequently, the influence of nozzle length on the turbulent flow within the nozzle can be understood, and the droplet formation characteristics of the liquid jet can be predicted along with its multi-wavelength dispersion characteristics. The model effectively captures the experimental results in terms of breakup length and droplet dispersion characteristics, thus adding a higher level of accuracy to numerical simulations. Ultimately, the in-depth study of this model, coupled with its comparison with experimental results, enhances the understanding of the liquid jet atomization process. [ABSTRACT FROM AUTHOR]

This study was aimed to evaluate the effect of diesel fuel temperature on engine performance and emissions. A 4-cylinder 4-stroke water cooled direct injection (DI) diesel engine was tested at three fuel temperatures (50, 60 and 70) °C. The fuel temperatures were controlled by A thermoelectric cooling system (TEC) fixed on the fuel supply line before the injection pump. The engine was run with two speed levels, included 1200 and 1500 rpm, with constant load (full load). An electric dynamometer was connected to the engine to make load by electric heaters. Gas emission was measured using gas analyzer type AirRex - HG540 and Texa gas box. Results obtained from the experiment were statistical analyzed using the factorial experiment system. The experiment design is (CRD), the averages of the results were tested using the least significant difference (LSD) at the probability level (0.05) using the (Genstat) program and showed that the fuel temperatures (50 °C) detected a sharp reduction in each of the brake specific fuel consumption (BSFC) by (6.95,4.34%), Exhaust Gas Temperature(EGT) by (4.98,2.38%), Nitric Oxide (NOx) by )29.09,27.08%), and Particulate matter (PM) by (46.25,31.25%) and registered a slight increase brake thermal efficiency (BTE) of (7.12,4.40%) respectively, compared to the fuel temperature of (60,70) °C. [ABSTRACT FROM AUTHOR]

This study was aimed to evaluate the effect of blending two types of alcohol with pure diesel fuel. A 4- cylinder 4- stroke water cooled direct injection (DI) diesel engine was used. An electric dynamometer was connected to the engine to make load by electric heaters; the load on the engine was fixed at full load. The engine was run with two speed levels : 1300 rpm and 1600 rpm. Three types of fuel were used, including blended n- butanol (B) and Acetone(A) mixed with diesel by two levels named by AB15D85 and AB30D70, respectively, and compared with pure diesel fuel (D), which was the baseline. Gas emission was measured by using gas analyzer type AirRex - HG540. Results obtained from the experiment were statistically analyzed and showed that brake thermal Efficiency registered a slight increase of 5.7% when using(AB30D70) compared with base diesel fuel, while the samples (AB30D70, AB15D85) pointed to a slight increase in BSFC by (5.1%and4.4%) respectively when compared with base diesel fuel. The fuel(AB30D70) detected a sharp reduction in both carbon dioxide (CO2) unburned hydrocarbon(HC) and Nitrogen oxides (NOx) by (49.1%,100%, 38%) respectively compared with base diesel fuel. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the L.N. Gumilyov Eurasian National University. Technical science & Technology series is the property of L.N. Gumilyov Eurasian National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To enhance air–fuel mixing and turbulence during combustion, spark ignition internal combustion engines commonly employ tumble vortices of the charge inside the cylinder. The intake phase primarily dictates the generated tumble, which is influenced by the design of the intake system. Utilizing steady-state flow rigs provides a practical method to assess an engine's cylinder head design's tumble-generating characteristics. This study aims to conduct computational fluid dynamics (CFD) numerical simulations on various configurations of steady-state flow rigs and compare the resulting tumble ratios. The simulations are conducted for different inlet valve lifts of a four-valve cylinder head with a shallow pent-roof. The findings highlight variations among these widely adopted configurations. [ABSTRACT FROM AUTHOR]

The study involved the utilization of novel developed six distinct fuel, denoted as, PG5, PG10, PG15, PG20, PG25, and PG30 and G100 (pure gasoline). These fuels were derived from various blends of gasoline and phthalocyanines. Experimental investigations were conducted to assess the internal combustion engine's performance in terms of both energy and exergy. The mixtures underwent testing across a range of engine speeds, spanning from 1400 rpm to 3000 rpm. Notably, optimal performance across all fuels and engine speeds was consistently observed at 2600 rpm. In terms of energy and exergy efficiency assessments for all fuels and engine speeds, PG25 fuel demonstrated the highest efficiency levels, with 35% energy efficiency and 33% exergy efficiency at 2600 rpm. Conversely, G100 fuel exhibited the lowest energy and exergy efficiency at the same engine speed, registering values of 27% and 24%, respectively. Meanwhile, with regard to exhaust exergy, G100 fuel demonstrated the highest exhaust energy at 10.69 kW, occurring at 3000 rpm, whereas PG25 fuel exhibited the lowest exhaust exergy, measured at 3.09 kW. It has been observed that N2 gas, one of the exhaust components that affects the exergy of exhaust gases, affects the exhaust exergy to a large extent and this ratio is approximately 50%. In addition, the sustainability index value for all fuels was found to be at most 2600 rpm. It was calculated as 1.50 for PG25 fuel and 1.32 for G100 fuel. • The exergy of phthalocyanine as a fuel examined in internal combustion engines. • To increase efficiency of new fuels in the internal combustion engine. • The newly developed fuel has been shown to be more efficient than gasoline. [ABSTRACT FROM AUTHOR]

Hydrogen combustion engine vehicles have the potential to rapidly enter the market and reduce greenhouse gas emissions (GHG) compared to conventional engines. The ability to provide a rapid market deployment is linked to the fact that the industry would take advantage of the existing internal combustion engine production chain. The aim of this paper is twofold. First, it aims to develop a methodology for applying life-cycle assessment (LCA) to internal combustion engines to estimate their life-cycle GHG emissions. Also, it aims to investigate the decarbonization potential of hydrogen engines produced by exploiting existing diesel engine technology and assuming diverse hydrogen production routes. The boundary of the LCA is cradle-to-grave, and the assessment is entirely based on primary data. The products under study are two monofuel engines: a hydrogen engine and a diesel engine. The hydrogen engine has been redesigned using the diesel engine as a base. The engines being studied are versatile and can be used for a wide range of uses such as automotive, cogeneration, maritime, off-road, and railway; however, this study focuses on their application in pickup trucks. As part of the redesign process, certain subsystems (e.g., combustion, injection, ignition, exhaust gas recirculation, and exhaust gas aftertreatment) have been modified to make the engine run on hydrogen. Results revealed that employing a hydrogen engine using green hydrogen (i.e., generated from water electrolysis using wind-based electricity) might reduce GHG emission by over 90% compared to the diesel engine This study showed that the benefits of the new hydrogen engine solution outweigh the increase of emissions related to the redesign process, making it a potentially beneficial solution also for reconditioning current and used internal combustion engines. [ABSTRACT FROM AUTHOR]

Waste heat recovery from exhaust gas is one of the most convenient methods to save energy in internal combustion engine-driven vehicles. This paper aims to investigate a reduction in waste heat from the exhaust gas of an internal combustion engine of a serial Diesel–electric hybrid bus by recovering part of the heat and converting it into useful power with the help of a split-flow supercritical CO2 (sCO2) recompression Brayton cycle. It can recover 17.01 kW of the total 33.47 kW of waste heat contained in exhaust gas from a 151 kW internal combustion engine. The thermal efficiency of the cycle is 38.51%, and the net power of the cycle is 6.55 kW. The variation in the sCO2 temperature at the shutdown of the internal combustion engine is analyzed, and a slow drop followed by a sudden and then a slow drop is observed. After 80 s from stopping the engine, the temperature drops by (23–33)% depending on the tube thickness of the recovery heat exchanger. The performances (net power, thermal efficiency, and waste heat recovery efficiency) of the split-flow sCO2 recompression Brayton cycle are clearly superior to those of the steam Rankine cycle and the organic Rankine cycle (ORC) with cyclopentane as a working fluid. [ABSTRACT FROM AUTHOR]

In a global society that is increasingly interrelated and focused on mobility, carbon monoxide emissions derived from internal combustion vehicles remain the most important factor that must be addressed to improve environmental quality. Certainly, air pollution generated by internal combustion engines threatens human health and the well-being of the planet. In this regard, this paper aims to address the urgent need to understand and face the CO emissions produced by internal combustion vehicles; therefore, this work proposes a mathematical model based on Auto-Regressive Exogenous that predicts the CO percentages produced by an internal combustion engine during its start-up. The main goal is to establish a strategy for diagnosing excessive CO emissions caused by changes in the engine temperature. The proposed CO emissions modeling is evaluated under a real dataset obtained from experiments, and the obtained results make the proposed method suitable for being implemented as a novel diagnosis tool in automotive maintenance programs. [ABSTRACT FROM AUTHOR]

Internal combustion engines have been a major contributor to air pollution. Replacing these engines with electric propulsion systems presents significant challenges due to different countries' needs and limitations. An active, purely mechanical solution to the problem of irregular torque production in an alternative internal combustion engine is proposed. This solution uses an actuator built on a camshaft and a spring, which stores and returns energy during the engine operating cycle, allowing torque production to be normalized, avoiding heavy flywheels. Designed for control throughout the engine's duty cycle, this system incorporates a cam profile and a spring mechanism. The spring captures energy during the expansion stroke, which is then released to the engine during the intake and compression strokes. Simple, lightweight, and efficient, this system ensures smoother and more consistent engine operations. It presents a viable alternative to the heavy and problematic dual-mass flywheels that were introduced in the 1980s and are still in use. This innovative approach could significantly enhance the performance and reliability of alternative internal combustion engines without notable energy losses. [ABSTRACT FROM AUTHOR]

Heat transfer between combustion gases and walls is one of the most important phenomena for internal combustion engines; however, its mechanisms have not yet been elucidated. This study proposed a new model based on one-dimensional heat conduction to characterize and predict engine heat transfer. This model assumes a conduction thickness of a thermal boundary layer determined by heat conduction and strain. Through comparison with numerical simulation, it was found that the heat flux from the conduction-strain model was comparable to that in laminar heat transfer. The heat flux calculated with the conduction-strain model is considered to be the minimum heat flux under each operating condition and engine specification. Therefore, the ratio of the measured heat flux to modeled heat flux indicates the intensity of convection and radiation, particularly turbulent mixing. It was also found that the conduction-strain model reproduced the measured heat flux well with a single coefficient, exhibiting a small error of 10.2%; meanwhile, the errors of Woschni and Annand models were greater than 20%, suggesting that the proposed model has good potential in predicting the instantaneous heat flux more accurately than conventional models. [ABSTRACT FROM AUTHOR]

The present study describes an improvement of damping performance of a mechanical tensioner driven by friction force at the power spring interface, used for the timing chain system for an internal combustion engine. The mechanical tensioner consists of a power spring subjected to face-to-face contact with a reciprocal motion and a leaf spring to apply the reaction load. The concave and convex surface texture was fabricated with an electrochemical etching on the power spring surfaces. Since the reaction load is affected by the friction force at the power spring interface, the damping performance is evaluated from a hysteresis loop resulting in the reaction load and the plunger displacement trajectory. Superior stabilization of the reaction load and a remarkable decrease of the wear loss including the restriction of the oxidation was found on the convex textured tensioner in lubricated condition. The tensioner performance was also evaluated in staved lubricating conditions. Results showed that the change of the reaction load of the convex textured tensioner was small just before the stiction occurrence. In contrast, the reaction load of the concave textured tensioner increased with the increase in the number of cycles. Therefore, the applicability of the convex surface texture to the power spring surface of the tensioner was confirmed. It was also estimated that the discharge of the wear debris is an important factor in maintaining the tensioner performance.

In the presented research, the authors dealt with the specific properties of the combustion process of dimethyl ether (DME) in a combustion car (Volkswagen Golf IV) engine AJM 1.9 TDI PDE made by Volkswagen factory. Dimethyl ether is an alternative fuel produced most often from natural gas, which can be used in compression ignition engines as a single fuel or co-burned with diesel oil. This work describes the impacts of using exhaust gas recirculation system and various diesel to DME substitution ratios from 0% to approximately 25% (on an energy basis), on the combustion process in a dual-fuel diesel engine. The engine has been modified so that DME fuel is introduced into the intake manifold just before the intake valves. The diesel fuel supply system, operation algorithms of the engine electronic control unit and other engine elements were left unchanged as it was built by the manufacturer.

The increasing complex geological and hydrogeological conditions ore deposit mining, deeper excavation sites, and ambitious business expansion strategies, necessitate the use of high-performance, heavy-duty self-propelled machinery and winning equipment. Such activities significantly strain mine ventilation systems and demand innovative safety measures during mining. This study assesses the influence of interconnected production variables on the aerological safety of mining operations. It provides real-world data on emissions from diverse sources within mines. The analysis includes an examination of current methodologies for estimating the air volume needed to dilute exhaust gases from diesel-powered machinery. Through numerical simulation that accounts for changes over time, the study was able to predict how exhaust gas concentrations would disperse within mines. These theoretical findings were then confirmed through empirical observations made in actual mining setting The field studies conducted, alongside their thorough analysis, underscored the necessity for adopting new, more sophisticated approaches to calculate airflow requirements in mines operating ICE machinery. A particular methodology developed by the MMI of the NUST MISIS (hereinafter referred to as the Methodology) was put forward as the primary tool for this purpose. The Methodology’s precision and benefits were closely scrutinized, revealing its effectiveness in ensuring aerological safety in mines.