Four-stroke Engine Research Articles

Investigating the Potential of Plastic Pyrolysis Oil-Diesel Blends in Diesel Engine: Performance, Emissions, Thermodynamics and Sustainability Analysis

The abrupt rise in demand for conventional fuels has become a major cause for concern despite their increasing depletion. That's why the pyrolysis process to make plastic pyrolysis oil (PPO), can be used to prepare fuel as an alternative fuel. The batch pyrolysis reactor was fabricated to produce plastic pyrolysis oil (PPO) from locally sourced grocery bags made of high-density polyethylene (HDPE). The purpose of this study was to thoroughly analyze the performance and emission characteristics of an engine running on up to 15% PPO-diesel blended fuel. Then, the experimental data obtained from a single-cylinder, four-stroke engine with five distinct speeds ranging from 1000 to 3500 rpm were utilized to undertake energy, exergy, and sustainability assessments. The results showed that DPO5 had a maximum brake power of 1.92 kW at 2500 rpm. At 3500 rpm, the engine achieved a thermal efficiency of 47.44% for diesel and 51.6% for DPO5 blended fuel. Furthermore, DPO15 produced the least quantity of CO2 at all engine speeds. DPO5 has the highest sustainability index, 1.52 at 2500 rpm. As a result, our research found that a low-level PPO-diesel fuel blend may be effectively injected into diesel engines without requiring any modifications.

The Influence of the Intake Geometry on the Performance of a Four-Stroke SI Engine for Aeronautical Applications

In this work, the influence of plenum and port geometry on the performance of the intake process in a four-stroke spark ignition engine for ultralight aircraft applications is analyzed. Three intake systems are considered: the so-called “standard plenum”, with a relatively small plenum volume, the “V1 plenum”, with a larger plenum volume, and the “standard plenum” equipped with a large curvature manifold called the “G2 port”. Both measurements and 3D CFD simulations, by using Ansys® Academic Fluent, Release 20.2, are performed to characterize and analyze the steady-flow field in the intake system for selected valve lifts. The experimental data and the numerical results are in excellent agreement with each other. The results show that at the maximum valve lift, i.e., 12 mm, the V1 plenum allows an increase in the air mass flow rate of 9.1% and 9.4% compared to the standard plenum and the standard plenum with the “G2 port”, respectively. In addition, the volumetric efficiency has been estimated under unsteady-flow conditions for all geometries at relatively high engine rpms. The difference between numerical results and measurements is less than 1% for the standard plenum, thus proving the accuracy of the model, which is then used to study the other configurations. The V1 plenum shows a fairly constant volumetric efficiency as the engine speed increases, although such an efficiency is lower than that of the other two geometries considered in this work. Specifically, the use of the “G2 port” leads to an increase of 1.5% in terms of volumetric efficiency with respect to the configuration with the original manifold. Furthermore, for the “G2 port” configuration, higher turbulent kinetic energy and higher swirl and tumble ratios are observed. This is expected to result in an improvement of air–fuel mixing and flame propagation.

Investigations on animal fat biodiesel selected blend by varying the fuel injection pressures and timings in the four-stroke single cylinder compression ignition engine

In the earlier investigations on the animal fat biodiesel, the authors have found that blend 20 was suitable to run the engine. In the CI engines, operating input parameters, FIPs and FITs, are the significant parameters to improve the engine performance and emission characteristics. Biodiesel was prepared by the transesterification process and blended with 20% diesel fuel to get AFB20 blend and to carried out the experiments by varying the FIPs by 180, 200, 220 and 240 bars and FITs by 19°, 21°, 23°, 25° and 27° bTDCs. The experiments were investigated in the single-cylinder 4S CI engine. In the evaluation, it was found that the FIP of 200 bar and 180 bar consumes 0.96% lower BSFC compared to 240 & 220 bars and exhibits a higher BTE of 2.6%. 1.62% lower EGT was found in 240 bar compared to 180 bar. 0.86% lower UBHC and 24.67% lower smoke emissions were observed in 200 and 240 bars. Lower BSFC was found in the 23° IT and higher BTE was found in 19° IT. Lower EGT and UBHC emissions were found in 19° IT. Lower EGT and CO emissions were found in 19° CA and higher CO emission was found in 23° IT at full load.

Equivalent Simulation Study of Delta-Rotor Engine

The mechanical structure, movement mode, and combustion process of a triangular rotor engine differ from those of a conventional engine with a crank connecting rod mechanism as the core. This makes it impossible to directly use existing simulation software to simulate the performance of the entire engine, rendering it difficult to conduct structural evaluation and performance prediction during the engine development stage. Therefore, using existing performance simulation software to establish a performance-equivalent model for a triangular rotor engine is crucial. To solve the above problems, this study proposes a performance-equivalent simulation modelling method for a triangular rotor engine based on a three-dimensional simulation model and the operating principles of the triangular rotor and four-stroke engines. Compared to various performance indicators obtained from the three-dimensional simulation model, the results show that the equivalent model established in this study has sufficient accuracy for key indicators such as the cylinder pressure, cylinder temperature, and in-cylinder quality under various working conditions. This can satisfy the requirements of the complete machine-performance simulation of a triangular rotor engine.

Experimental Investigation on Performance Characteristics o f Diesel Engine Using Various Blended Biodiesels

Objectives: To evaluate the performance characteristics of diesel engines through experimental research with various biodiesel blends. Method: Three types of oils were chosen for this study: waste cooking oil, waste chicken oil, and palm oil. The methyl esters were produced from waste chicken oil (COME), waste cooking oil (WCOME), and palm oil (POME). The test runs were done on a 4.5 kW direct injection, air-cooled, four-stroke, single-cylinder, and constant-speed diesel engine using varied fuel at maximum load. Findings: This study finds performance analysis for a variety of methyl esters and diesel. The Brake Thermal Efficiency (BTE) was found to be: for Diesel (33.36%), POME (30.53%), WCOME (27.5%), COME (25.0%) at rated power (4.5) K.W. The brake thermal efficiency for palm oil methyl esters is similar to the diesel compared to the other methyl esters. Novelty: This research study provides a comparison between the diesel and methyl esters of break thermal efficiency for diesel engines. Keywords: Diesel Engine, Trans esterification, Biodiesels, Performance characteristics

МОДЕЛИРОВАНИЕ ПУСКА ДВС АВТОМОБИЛЯ С БЕССТУПЕНЧАТОЙ КОРОБКОЙ ПЕРЕДАЧ

The aim of the work is to build a computer dynamic model of moving internal combustion engine parts and a continu-ously variable transmission to determine the starting characteristics of the internal combustion engine. The paper objective is to define the characteristics of moving parts of the internal combustion engine and continuously variable transmission when starting the internal combustion engine with an electric starter. The research method is computer modelling of moving internal combustion engine and transmission parts when starting with an electric starter. The novelty of the work lies in building a computer model of moving parts of an internal combustion engine and a contin-uously variable transmission, connected by a torsional vibration damper, considering changes in friction parameters. The results are in developing a computer model to determine the starting characteristics of a four-cylinder in-line four-stroke internal combustion engine with spark ignition and a continuously variable multitronic® 01J transmis-sion. To check the computer model adequacy, the author uses the values of the average friction pressure in accord-ance with GOST R 54120-2010 and empirical data on the unevenness of the angular velocity of the crankshaft. Simu-lating a four-stage start of an internal combustion engine shows that opening the cylinder valves at the 1st stage in-creases the angular velocity of the crankshaft by 4%. Temporary switching on the reverse clutch for 1.4 s reduces the amplitude of angular oscillations of the solar shaft by 2.22 times, eliminates the beating of the contacting gearbox teeth, but slows down the crankshaft speed by 7.6%. After the reverse clutch is turned off, periodic changes in the an-gular velocity of gearbox parts occur.

Evaluating Engine Performance, Emissions, Noise, and Vibration: A Comparative Study of Diesel and Biodiesel Fuel Mixture

This study investigates the performance, emissions, noise, and vibration characteristics of a single-cylinder, air-cooled, four-stroke diesel engine running on pure diesel (D100) and biodiesel blends (B10: 90% diesel, 10% biodiesel; B20: 80% diesel, 20% biodiesel) at 1800 rpm, where the engine delivers maximum torque. Key metrics such as torque, power, brake specific fuel consumption (BSFC), exhaust gas temperature, noise, vibration, and emissions (CO, CO2, HC, O2, NOx, and smoke opacity) were analyzed. The findings indicate that B10 enhances torque, power output, and overall fuel efficiency, especially at low to medium loads, with a significant 17.54% reduction in BSFC compared to D100 at 40% engine load. Vibration levels generally increased with biodiesel addition, while B10 and B20 both reduced smoke opacity, with B20 having a more substantial effect. HC emissions decreased at idle with B10 but increased at higher loads, suggesting more complete combustion with potential thermal stress on engine components. Noise and vibration results were mixed; B20 reduced noise at higher loads but increased vibration. At 100% load, B20 decreased noise by 1.42% compared to D100. Despite benefits such as improved torque and reduced particulate emissions, biodiesel blends, particularly B20, led to increased NOx and CO2 emissions, emphasizing the need for further op-timization of blend formulations and emission control strategies. This study provides valuable insights into the tradeoffs and potential of biodiesel blends as sustainable diesel alternatives.

Comparative analysis of spark ignition engine performance using RON 95 and RON 100 gasoline fuels

Most of the vehicles used by Malaysians have engines that only require petrol RON 95 to power the engine. However, many people claimed that utilising RON 100 instead of RON 95 for their vehicles will improve engine performance. Furthermore, many people speculate that using oil with a low octane level in an engine with low performance will affect the engine's performance. The goal of this research is to analyse and compare the engine performance and emissions on a spark ignition engine using gasoline RON 95 and RON 100. In this study, a single-cylinder four-stroke engine running with RON 95 and RON 100 has been tested on an engine dynamometer to evaluate the brake power, torque, specific fuel consumption, and exhaust emissions. The emissions from the engines have been determined using a gas emissions analyser. The outcomes of the experiment have been analysed based on engine torque, braking power, and exhaust emissions. Based on the analysis, torque, brake power, and emissions data obtained from the dynamometer engine, RON 100 has a higher and smoother performance than RON 95.

Experimental investigation of emissions from a single-cylinder diesel engine using methanol–diesel blends

This study examines the effects of methanol–diesel blends on the emissions of a diesel engine, concentrating on carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), hydrocarbons (HCs), and particulate matter (PM). Using a single-cylinder four-stroke diesel engine at varying torque settings (2 N m–6 N m), significant reductions in CO, CO2, HC, and PM emissions were observed with increasing methanol content. CO emissions reduced by up to 81.8%, CO2 by up to 64.2%, HC by up to 80.4%, and PM by up to 23.5% with the MD11 blend. NOx emissions initially increased but decreased by up to 20% at higher torques with the same blend. These results highlight the environmental benefits of methanol–diesel blends and the need for effective NOx reduction strategies.

Numerical Analysis of the Effect of Ethanol-Gasoline Blends on a Single-Cylinder Spark-Ignition Engine Performance and Emissions

— With the rapid increase in the number of vehicles fueled by gasoline plying on the roads, there has been a rising need in the search for alternative fuels, which are more environmental friendly in order to reduce the amount of vehicular exhaust emissions. This can be achieved by using blended mixtures of gasoline with alcoholic fuels among which, ethanol is found to be most suitable due to its easy availability, low costs, safety and low impact on the engine performance. This study aims to investigate the performance of a single-cylinder, four-stroke spark-ignition engine using different ethanol-gasoline blends, namely E0, E10, E20 and E30. The engine's torque, brake power, brake thermal efficiency, brake-specific fuel consumption, and exhaust emissions were analysed using numerical simulation. Results revealed that raising the proportion of ethanol in the fuel mixture resulted in reduced brake power and torque upto 16% as a result of decrease in calorific value of the mixture. The engine's brake thermal efficiency decreased by upto 3% while the brake-specific fuel consumption increased upto 12% with increase in ethanol concentration. Exhaust emissions, including NOx and HC, were found to be influenced by engine speed, with NOx emissions increasing and HC emissions decreasing as speed increased. The study also revealed that increasing ethanol concentration in the fuel resulted in reduced engine exhaust emissions by upto 47% and 10% for NOX and HC emissions respectively. The study concluded that among all the blends used, optimum performance was obtained for E30 blend with reduction in exhaust emissions but at the expense of slight reduction in engine performance.

Applied AMT machine learning and multi-objective optimization for enhanced performance and reduced environmental impact of sunflower oil biodiesel in compression ignition engine

Biodiesel has emerged as a compelling substitute for conventional diesel fuel, providing a sustainable and eco-friendly choice for fueling compression ignition engines. This comprehensive study investigates the influence of biodiesel, specifically derived from sunflower oil, through the esterification method, on crucial engine performance parameters and environmental effects. The study examines the impact of varying engine torque on the performance of a single-cylinder, four-stroke compression ignition engine, encompassing parameters such as brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), as well as exhaust emissions, including unburned hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx). Four distinct biodiesel blends (B10, B20, B30, B40) with varying sunflower oil content are systematically compared to pure diesel (B0). The engine operates at a consistent speed of 1700 rpm, while the torque undergoes controlled adjustments from 0 to 10 Nm. Subsequently, this study explores the application of an alternating model tree (AMT) machine learning algorithm to establish relationships between independent factors, specifically torque and biodiesel volume (%vol), and dependent variables, including BTE, BSFC, CO, and NOx in a combustion engine. Additionally, the study employs a multi-objective ameliorative whale optimization algorithm (AWOA) to optimize the model's output. The objective is to identify optimal values for torque and%vol that maximize engine performance (BTE) while minimizing engine emissions (CO and NOx) and reducing fuel consumption (BSFC). The optimization process yields noteworthy results, with AWOA achieving peak BTE at 29.714 %, BSFC at 0.262 kg.kWh-1, and NOx emissions at 992 ppm at torque 7.3 N.m and 13% vol. In contrast, particle swarm optimization (PSO) secured the minimum CO level at 0.123 %, with torque set at 7.6 N.m and 26% vol. The AMT models demonstrate high prediction accuracy, with coefficient of determination (R2) values exceeding 0.98.

Greenhouse gas emissions of shipping with onboard carbon capture under the FuelEU Maritime regulation: A well-to-wake evaluation of different propulsion scenarios

International shipping has extended its decarbonization strategy to reduce greenhouse gas emissions beyond onboard CO2 emissions. Onboard carbon capture and storage systems are being investigated as a potential solution for fossil-fueled ships, however there is a lack of knowledge on the reduction of well-to-wake greenhouse gas emissions that could be enabled. Considering the ambitious emission reduction targets, this may lead to inaccurate estimations of the future fuel mix in the maritime sector and the market share of marine engines. This study defines nine ship propulsion scenarios based on combinations of fossil fuels and marine engines. To better understand the greenhouse gas emission reduction of onboard carbon capture, this study calculates the well-to-wake greenhouse gas intensity of each scenario with and without onboard carbon capture and storage from the ship’s main engine(s). Deploying onboard carbon capture and storage systems notably reduces the tank-to-wake greenhouse gas intensity (54–68 % depending on the scenario). Contrary to onboard emissions, oil-fueled ships with onboard carbon capture and storage are found to be less greenhouse gas intensive and more cost-effective than LNG-fueled ships. The four-stroke oil-fueled engine achieves the lowest well-to-wake greenhouse gas intensity of 38.31 gCO2eq/MJ, while the four-stroke LNG-fueled engine has the highest intensity of 50.34 gCO2eq/MJ. The greenhouse gas emission levels enabled by onboard carbon capture from the main engine would allow fossil-fueled ships to comply with the FuelEU Maritime greenhouse gas intensity requirement until 2044. To be compliant in subsequent periods, onboard carbon capture and storage systems will need to consider carbon capture from the auxiliary boiler and generator and higher capture rate, as well as measures to reduce upstream emissions from fossil fuel production and transport.

Creep assessment of thermoplastic materials for non-structural components in marine engines

The substitution of metals with fiber-reinforced polymers represents a well-established practice in the automotive and aerospace industries, driven by advantages such as cost reduction, weight savings, and environmental benefits. In the marine engineering sector, there is a growing interest in this metal replacement trend, particularly for non-structural components of marine engines that can be produced by adopting proper fiber-reinforced thermoplastic polymers. However, evaluating the suitability of such materials for marine applications necessitates a thorough understanding of their creep behavior, given the demanding operational environments and strict safety standards. The material selection process must intricately consider the material's susceptibility to creep through tailored material design methodologies. Moreover, redesign activities should aim to leverage the material's creep-resistant properties while ensuring adequate strength and simplifying installation procedures. Unfortunately, unlike the automotive industry, testing innovative plastic components in real environments on working engines is quite impossible. Neither engine manufacturers nor owners would allow jeopardizing their machinery by installing technologies not yet certified in a delicate environment such as a ship's engine room. In this context, finite element simulations offer a valuable tool to assess the material's creep performance and validate the proposed design when experimental measurements cannot be performed, hence predicting the component behavior over its intended lifetime. This study aims to exploit finite element analysis to evaluate the creep behavior and suitability for marine engine applications of a fiber-reinforced thermoplastic material, focusing on a camshaft cover of a four-stroke marine engine currently manufactured from aluminum alloy. Through numerical simulations, a commercial 30 % wt GFs/PA6,6 thermoplastic composite emerges as a promising candidate, demonstrating adequate creep resistance while significantly reducing weight, processing costs, and energy consumption. The results obtained from the present study lay the foundations for the adoption of such material-based technology also in the marine engine sector despite the difficulties coming from the peculiarities of this industry.

Parameter optimisation of marine four-stroke engine EGR systems using RSM and NSGA-III

ABSTRACT To reduce NOx emission of marine engines, an engine parameter optimisation method combining response surface method (RSM), Bayesian neural network and non-dominated sequence genetic algorithm (NSGA-III) is proposed. First, a simulation model of a marine four-stroke engine with an external exhaust gas recirculation (EGR) system was established and validated in AVL-BOOST software. Then, the five parameters of EGR valve opening, ignition advance angle, compression ratio (CR), intake valve opening (IVO) and exhaust valve closing (EVC) are selected as the decision parameters, and the three parameters of engine power, brake specific fuel consumption (BSFC) and NOx emission are taken as the target parameters to be optimised. In Design-Expert software, the response surface model is established by using the experimental design approach of central composite design (CCD), and the impact of decision parameters on target parameters are discussed by using response surface analysis. NSGA-III was used for the multi-objective optimisation of parameters, and the accuracy of NSGA-III was improved by the Bayesian neural network. The optimal solution is selected and verified by the technique for order of preference by similarity to the ideal solution (TOPSIS) approach. The results show that when the EGR valve opening is 47.5%, ignition advance angle is −18.99°CA, CR is 14.995, IVO is 15.27°CA and EVC is 7.68°CA, compared with the standard setting, the optimised power is increased by 4.17%, BSFC is reduced by 4.27%, and NOx emissions are reduced by 12.37%. Therefore, the combination of the Bayesian neural network and NSGA-III multi-objective optimisation can improve engine performance while reducing fuel consumption and NOx emissions.

Numerical and experimental analyses for performance and emissions assessment of a four-stroke engine powered by oleic acid methyl ester biofuel made from waste frying oil

<p style="text-align:justify"><span style="font-size:11pt"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman",serif">Recently, several earlier works conducted research works dedicated to replacing fossil-based fuels with environmentally friendly ones. The goal of the research is to construct a multivariate linear regression model for the attributes of a four-cylinder diesel engine fueled by biodiesel. In this context, the goal of the research is to structure a multiple linear regression example for characterizing a four-cylinder engine fueled by biodiesel. In fact, experimental research was conducted on an agricultural tractor equipped with a 4-cylinder direct-injection diesel engine. The biodiesel is made from waste frying oil without blending referred to as the oleic acid methyl ester (OAME) biofuel. The biodiesel was extracted through a chemical transesterification reaction. The four-stroke engine is tested for both pure OAME biofuel and conventional diesel. One-dimensional numerical simulations were conducted. A strong correlation between numerical and experimental data was observed, validating the numerical model. Using the engine model, in-cylinder pressure, heat release rate, in-cylinder temperature, and emissions including Carbon monoxide (CO), nitrogen oxides (NO<sub>x</sub>), and Carbon dioxide (CO<sub>2</sub>) were recorded across a broad range of engine operating speeds. Additionally, brake-specific fuel consumption (BSFC) and brake power were numerically calculated and compared to experimental data. The results showed that usage of the OAME as a biofuel could be a promising solution that enables similar performances with lower CO emissions compared to petroleum diesel particularly at low engine speeds.</span></span></span></span></span></span></p>

Assessment of reactive-control compression ignition engine performance and emissions using spirulina microalgae biodiesel in conjunction with methanol as low-reactive fuel

AbstractDue to their numerous uses and great fuel economy, diesel engines have been around for millennia. Despite these benefits, diesel engines have been found to pollute the environment severely. Most of the problems were caused by these engines' combustion processes, engine loads, and exhaust particles. The RCCI engine used in the experiment has 20% lower fuel and 80% high reactive fuel. In this research, methanol, and algae biodiesel blends with dimethyl ether acted as lower and higher reactive fuels, respectively, and these fuels were used to analyze the performance and emission in the RCCI engine. Among the 80% of high reactive fuel, blends contain different proportions of algae biodiesel and diethyl ether such as 32B, 28B4ME, 24B8ME, 20B12ME, and 16B16ME. A single-cylinder, four-stroke RCCI engine with a speed of 1500 rpm is used for the experiment. In the tests, the brake power is varied from 1 to 5 kW with an interval of 1 kW. In the results, BTE, BSFC, and EGT engine performance as well as NOX, HC, CO2, and smoke emissions. According to the experimental findings, the fuel properties of 16B16ME show a calorific value of 34.7 /MJ kg-1 and BTE shows improvement for all additive added fuel and 16B16ME shows higher BTE of 32.5% than other fuel blends, Similarly NOx emission also reduced for 628 ppm for 16B16ME than other fuel blends. Therefore 16B16ME is a suitable blend than other blends in RCCI engine based on the experimental results achieved in the present research.

Using DPF to Control Particulate Matter Emissions from Ships to Ensure the Sustainable Development of the Shipping Industry

PM (particulate matter) emissions from ships are the main sources of marine atmosphere pollution. Controlling the emissions of particulate matter from ships is related to the sustainable development of the shipping industry. To reduce PM emissions from marine four-stroke diesel engines, DPFs are effective. Our results show that DPF had more than 90% capturing efficiency for both the number and mass emissions of PM, and the capturing efficiency for the accumulation mode was higher than that of the nuclear mode. DPF can also significantly reduce the chemical components of PM in marine diesel exhaust gas. The removal efficiencies for OC and EC were 89.7–91.6% and 84.8–92.8%, respectively, with each particle size range showing over 80% efficiency. SO42− was the ion with the highest content, followed by NH4+, NO3−, Na+, NO2−, and Cl−, with their reduced proportions remaining consistent with the removal efficiency of particulate matter. DPF can also effectively reduce PAH content and toxicity. The use of DPF can greatly improve the impact of ship emissions on the marine atmospheric environment. The appropriate DPF with the best performance can be selected according to the exhaust parameters and particle size distributions with different characteristics.

The Effect of Using Crankcase Emission Control System Technology on the Performance of a 160 cc Single Cylinder Four Stroke Engine

The research was carried out on a single-cylinder four-stroke petrol engine with a rotation variation of 1000 rpm - 9000 rpm, using crankcase emission control system (CECS) technology. The air that will enter the carburetor is mixed with hot gas that flows and comes from the CECS, causing the air to become warm and then mixed with the fuel in the carburetor and then the mixture passes through the manifold into the combustion chamber. Investigation in the first stage under standard conditions and in the second stage using CECS technology. The use of CECS technology results in increased machine performance. After testing with and without using CECS technology, optimum performance in the form of power, torque and specific fuel consumption occurred at engine speeds of 8000 rpm, 6000 rpm and 7000 rpm respectively producing power, torque and specific fuel consumption of 13.11 ; 1.504 kg.m and 0.152 kg/hp.hour without CECS, and with the use of CECS technology of 13.20 hp; 1.56 kg.m and 0.151 kg/hp.hour.

Evaluation of ethanol-gasoline blends in SI engines using experimental and ANN techniques

Fuel combustion has become a major global concern, with much research focusing on the various emissions resulting from different types of fuels. Due to the harmful pollutant emissions from fossil fuels, the world has turned to renewable and alternative fuels to limit toxic emissions and greenhouse effects. Ethanol is a biofuel that, when used in spark ignition engines with gasoline can improve the octane number, combustion efficiency, and produce less emissions. The current research studies the effect of different ethanol blends E0, E5, E10, and E15 with gasoline 92 on engine performance parameters and emissions of a GX35 four-stroke engine at different engine speeds. The results along the speed range reveal that increasing ethanol amount leads to an average increase of 2.7%, 1%, and 1.1% in brake power (BP), brake thermal efficiency (BTE), and CO2 emissions, respectively. Meanwhile, it causes an average decrease of 28 °C, 3%, 15 ppm, and 0.18% in exhaust gas temperature (EGT), brake-specific fuel consumption (BSFC), HC, and CO emissions respectively. Moreover, the current study develops an Artificial Neural Networks (ANN) model for predicting the performance and emissions of spark ignition (SI) engines. Python programming language is used for ANN coding to train and validate the ANN model with E15. Regression plots were generated to visualize the correlation between the target and predicted data, indicating outstanding performance. The results confirmed the model’s reliability for BP, EGT, CO, CO2, and HC parameters with R2 values more than 0.99 and with acceptable performance for BSFC and BTE with R2 of 0.9339, and 0.9708, respectively. To ensure that the is no overfitting during the ANN study, we used different statistical methods, such as validation set, cross-validation, and learning curves.

Experimental Optimization of Natural Gas Injection Timing in a Dual-Fuel Marine Engine to Minimize GHG Emissions

Phased injection of natural gas into internal combustion marine engines is a promising solution for optimizing performance and reducing harmful emissions, particularly unburned methane, a potent greenhouse gas. This innovative practice distinguishes itself from continuous injection because it allows for more precise control of the combustion process with only a slight increase in system complexity. By synchronizing the injection of natural gas with the intake and exhaust valve opening and closing times while also considering the gas path in the manifolds, methane release into the atmosphere is significantly reduced, making a substantial contribution to efforts to address climate change. Moreover, phased injection improves the efficiency of marine engines, resulting in reduced overall fuel consumption, lower fuel costs, and increased ship autonomy. This technology was tested on a single-cylinder, large-bore, four-stroke research engine designed for marine applications, operating in dual-fuel mode with diesel and natural gas. Performance was compared with that of the conventional continuous feeding method. Evaluation of the effect on equivalent CO2 emissions indicates a potential reduction of up to approximately 20%. This reduction effectively brings greenhouse gas emissions below those of the diesel baseline case, especially when injection control is combined with supercharging control to optimize the air–fuel ratio. In this context, the boost pressure in DF was reduced from 3 to 1.5 bar compared with the FD case.