Diesel Engine Combustion Research Articles

A grey wolf optimization approach for evaluating the engine responses of various biodiesel blends in an internal combustion engine

The knowledge of the exact thresholds of parameters in the diesel engines, during combustion, is essential to simulate the combustion process, establish parametric values, reduce cost and predict exhaust emissions. Accordingly, the present paper applies the grey wolf optimization method to determine the optimal threshold of parameters and engine responses in a direct ignition engine. Twelve formulated linear equations of engine responses are introduced to the objective function of the grey wolf optimizer. A computer program in C++ was applied successfully using literature data to validate the grey wolf optimization procedure based on the encircling, hunting and attacking of prey by the wolf. The results show that load demand and turbocharge boast air pressure have the least and highest values of engine outputs, respectively. The blend ratio had its highest values when optimized alongside the main injection duration. The responses and parameters greatly improved from initial values to stopping criterion of 200 iterations. Instances reported include brake specific fuel consumption, which improved from 2.6468 to 1.0816 g/kWhr, blend ratio changes from 0.5031 to 0.4760%, speed drop from 0.0031 to 0.0010rpm, and load drop from 0.0017 to 0.0010%. The main contribution of this paper is to establish the optimal thresholds of engine responses using the grey wolf optimizer in a diesel engine combustion chamber. The development of a new method to optimize response and parameters of an internal combustion process using grey wolf optimizer is the novel aspect of this work. The results have essential practical significance to establish new emission profile for biodiesel. The practising engineers and researchers have a holistic insight into the problem’s solution and can utilize the results to enhance their engine responses.

A study on misfire control using crank angular velocity combustion feedback considering in-cylinder gas properties

Internal combustion engines have been strongly required to improve thermal efficiency and utilize a variety of fuels derived from renewable energy sources to achieve carbon neutrality. In terms of engine development, the stable control of ignition and combustion is the primary challenge in adapting to diverse fuels for the recently emphasized premixed compression ignition combustion and super lean burn. In this study, a misfire index was used as a detector for a premixed type of diesel combustion engine. Combustion feedback control was performed to control the target value of EGR based on the difference between the misfire index and its target value. To apply crank angle velocity to feedback control, this study implemented corrections and limitations to the misfire index based on in-cylinder gas properties. This was made possible because, during misfire events, the in-cylinder pressure at top dead center (TDC) is not influenced by combustion pressure. Additionally, this research enabled model validation of the phenomena for the first time. A novel structure was also established to learn the EGR correction amount from the deviation of the misfire index, marking the first empirical demonstration of its effectiveness. This research not only presents control examples for misfire countermeasures, which are crucial for the development of engines capable of utilizing diverse fuels but also contributed to mass production and practical application.

Investigating The Combustion Performance of Dual Fuel Combustion With Diesel and Port Injected Hydrogen In A Large Bore Locomotive Engine

Abstract The heavy-duty transportation sector has primarily relied on conventional diesel combustion engines given their reliability and high thermal efficiency relative to spark ignition engines, but increased focus on reducing greenhouse gas emissions has led to investigation into alternative fuels. Gaseous hydrogen fuel has garnered a great deal of recent interest in the engine community given it has zero carbon, but hydrogen is not available at the scale and cost that petroleum fuels are currently available, and this is a barrier to adoption for industries that are looking to decarbonize their operations. Because of the fuel flexibility provided, dual fuel technology offers a pathway for some industries to adopt hydrogen as a fuel source while maintaining sufficient flexibility in times and locations where the new fuel is not yet available. This computational study investigates dual fuel combustion in a large bore locomotive engine architecture using direct injected diesel and port injected gaseous hydrogen fuel. With an optimal port fuel injection configuration from previous work [18], simulations of varying substitution ratio, compression ratio, intake manifold air temperature, diesel injection timing, and diesel injection pressure were performed to understand their effect on combustion performance. Results indicated that both increased substitution ratio and higher intake air temperature accelerates hydrogen flame propagation and can result in high peak cylinder pressures. Additionally, diesel injection timing and injection pressure were demonstrated as effective methods for controlling dual fuel combustion heat release rates.

Performance and emissions of diesel engine combustion lubricated with Jatropha bio-lubricant and MWCNT additive

Vegetable oil-based lubricants, modified through transesterification and epoxidation, present a sustainable alternative to mineral lubricants for transport and industrial use. This study evaluates epoxidized jatropha oil (EJA) enhanced with multi-walled carbon nanotubes (MWCNT) as a bio-lubricant for compression ignition engines. MWCNT, dispersed in EJA using an ultrasonic probe sonicator with Triton X-100 as a surfactant, was tested at nanoparticle concentrations from 0.5 to 2 wt%. Engine performance and emission characteristics were assessed using SAE 20W40, EJA, and EJA-MWCNT in a four-stroke diesel engine. Results showed that EJA with 2 wt% MWCNT reduced friction power by 39.13% compared to SAE 20W40 and decreased brake specific energy consumption by 6.11%, while lowering emissions of hydrocarbons, carbon monoxide, and smoke. These findings highlight EJA-MWCNT as a promising lubricant for diesel engines, enhancing efficiency and reducing pollutants, making it a viable eco-friendly substitute for diminishing petroleum resources.

Influence of 1-Hexanol/Waste Plastic Oil Blends on Combustion, Performance, and Emission Characteristics of a Common Rail Direct Injection Diesel Engine.

Waste plastic oils (WPOs) can help address the global energy crisis caused by the rapid depletion of fossil fuels, global warming, and strict emission regulations. The present research delves into the intricate interplay of higher alcohol blends in the context of combustion, performance, and emission characteristics within a common rail direct injection engine. In this regard, 1-hexanol has been selected as the blending constituent for the WPO to tackle emission challenges while concurrently reducing dependence on conventional fuel, as it stands out for its enhanced fuel properties compared to lower alcohols. Simultaneously, the investigation took into account the influence of varying exhaust gas recirculation (EGR) rates. Experimental scrutiny centers on 10 to 30% by volume of 1-hexanol content with the WPO blends for the engine running at 2000 rpm at 20 to 80% of engine load. The inclusion of 1-hexanol led to a maximum cylinder pressure of 86.42 bar, a heat release rate of 117.43 J/degree, and a brake thermal efficiency of 42.1%. Brake-specific energy consumption values decreased with increasing hexanol concentration, demonstrating improved fuel economy. However, emission analysis revealed that HC emissions increased with the hexanol concentration, reaching a maximum of 45 PPM for the H30WPO70 blend at low loads. Similarly, CO emissions were highest for the H30WPO70 blend, with a peak value of 0.40%vol at 20% load. NOx emissions, on the other hand, decreased with increasing hexanol content and EGR rates with a reduction of 11.3 and 12.55% at 10 and 20% EGR respectively. Thus, the comprehensive investigation of 1-hexanol augmentation in waste plastic oil provides the intricate details of combustion processes and performance metrics with emission profiles, which entail the 1-hexanol integration as an effective means for characteristic improvement of automotive engines.

Risk assessment of particle and gaseous emissions from diesel and methanol–diesel advanced dual-fuel engines

The study investigates the influence of engine load and methanol energy share on the ultrafine particulate matter (PM) and unregulated emissions from advanced dual-fuel (reactivity-controlled compression ignition (RCCI)) and conventional diesel combustion (CDC) engines. An automotive diesel engine was modified to operate in RCCI mode by integrating a port fuel injection system with methanol. Real-time PM and gas-phase emissions were measured using a DMS 500 particle sizer and FTIR (Fourier-Transform Infra-Red) emission analyser. The study aims to evaluate the effect of combustion modes and operating conditions on exhaust emissions and their effect on human health and the environment. A comprehensive toxicity assessment was conducted which included quantifying the cytotoxicity on BEAS-2B epithelial lung cells exposed to PM, assessing lung retention of PM particles due to inhalation, and determining the cancer risk potential from carbonyl emissions. The risk assessment findings show that RCCI engine-emitted PM particles exhibit lower lung retention than those from the CDC engine. Furthermore, the environmental impact assessment reveals that RCCI engines emit unregulated emissions and exhibit lower global warming potential, acidification potential, and eutrophication potential than CDC engines. Notably, RCCI engines that emitted unsaturated HCs (Hydrocarbons) and carbonyl emissions show higher ozone-forming potential and cancer risk potential.

Progressive split injection strategies to combustion and emissions improvement of a heavy-duty diesel engine with ammonia enrichment

Progressive split injection strategies to combustion and emissions improvement of a heavy-duty diesel engine with ammonia enrichment

An Artificial Intelligence-based strategy for multi-objective optimization of combustion and emissions for diesel engine fueled with ammonia-diesel blended fuel with the addition of low-proportion hydrogen

An Artificial Intelligence-based strategy for multi-objective optimization of combustion and emissions for diesel engine fueled with ammonia-diesel blended fuel with the addition of low-proportion hydrogen

Impact of Fuel Additives on the Performance, Combustion and Emission Characteristics of Diesel Engine charged by Waste Plastic Bio-diesel

Impact of Fuel Additives on the Performance, Combustion and Emission Characteristics of Diesel Engine charged by Waste Plastic Bio-diesel

Research on Multi-objective Control of PPCI Diesel Engine Combustion Process Based on Data Driven Modelling

Research on Multi-objective Control of PPCI Diesel Engine Combustion Process Based on Data Driven Modelling

Evaluation of emissions and performance of a diesel engine running on graphene nanopowder and diesel-biodiesel-ethanol blends.

Today, there are environmental problems all over the world due to the emission of greenhouse gasses caused by the combustion of diesel fuel. The excessive consumption and drastic reduction of fossil fuels have prompted the leaders of various countries, including Iran, to put the use of alternative and clean energy sources on the agenda. In recent years, the use of biofuels and the addition of nanoparticles to diesel fuel have reduced pollutant emissions, improved the environment, and enhanced the physicochemical properties of the fuel. The current research deals with the experimental evaluation of emissions and performance of a diesel engine running on graphene nanopowder together with diesel-biodiesel-ethanol blends. The engine variables studied included the engine speed (in three stages 1800, 2200, and 2600rpm) and three types of fuel including graphene nanoparticles (with values of 25 and 50ppm), biodiesel (with volume percentages of 4, 6, and 8), and ethanol (with volume percentages of 2 and 4). The results showed that the power and torque of the D86 + B8 + E6 + G50 fuel increased on average by 20.26% and 28.76% at all engine speeds compared to the D100 fuel. The use of D86 + B8 + E6 + G50 fuel resulted in a significant reduction in CO (38.84%), UHC (21.24%), and NOx (19.92%) emissions compared to D100 fuel. In addition, a significant increase in CO2 emissions (23.19%) was observed. The results of this study clearly show that the use of biofuels and the addition of nanopowder to D100 fuel are very effective methods to improve combustion, performance, and emission characteristics in diesel engines.

Critical Review on Effect of CI Engine Performance and Emission from Nano Particle Blended Biodiesel Combustion at various fuel injection pressures

In recent years, Due to the depletion of petroleum reserves and rising environmental concerns, alternative fuels have attracted a lot of attention. This study investigates the combustion, emissions, and performance properties of diesel engines running on biodiesel-diesel blends. Recent developments in nanotechnology have made it possible to use fuel injection pressures and nanoparticle fuel additives in internal combustion engines. By adding nanoparticles to biodiesel-diesel blends, the amount of brake specific fuel is reduced. Additionally, nanoparticles have a high thermal conductivity, which improves combustion and brake performance . According to the reviews, NOx emissions increased while HC, CO, and PM emissions reduced. The results show that biodiesel and biodiesel blends as a fuel for CI engines might significantly enhance performance while reducing emissions by adding nanoparticles and fuel injection pressures.

Impact of nano cerium oxide addition with pyrolysis waste plastic oil on combustion, performance and emission characteristics of CRDI diesel engine

Abstract This investigation examined the effect of incorporating cerium oxide (CeO2) nanoparticle into diesel and waste plastic oil (WPO) blends on the combustion, performance and emission characteristics of the diesel engine. The WPO was extracted from low density polyethylene using plastic pyrolysis. The blending of diesel and WPO with combination of D70:WPO30 and D50:WPO50 was prepared to evaluate the engine operation. Additionally, the spherical sized CeO2 with 50 mg l−1 and 100 mg l−1 was added with this blend. The various blends named as Diesel, D-WPO30, D-WPO30+Ce50, D-WPO30+Ce100, D-WPO50, D-WPO50+Ce50 and D-WPO50+Ce100 were used in this investigation to operate the engine under various load conditions. The experiment was performed using water cooled common rail direct injection (CRDI) diesel engine with prepared D-WPO blend. Different characteristics such as In-cylinder pressure (CP), heat release rate (HRR), ignition delay time (IDT), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust gas temperature (EGT), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOx) and smoke opacity emission are studied with respect to the effect of different blends and applied load used. It was observed that increasing of CeO2 nanoparticles in blend improved the overall performance and emission of the engine. Form the results, D-WPO30+Ce100 blend showed enhanced brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust has temperature (EGT) are 28.2%, 3% and 465 °C respectively. Similarly, reduced emission of CO, NOx, HC and smoke opacity was observed in the CeO2 added blends particularly at 100 mg l−1. It was concluded that among all blends prepared, the D70:WPO30 with 100 mg l−1 of CeO2 showed improved combustion, performance and emission characteristics in proposed diesel engine.

Optimization of Second-Generation Biodiesel Blends to Enhance Diesel Engine Performance and Reduce Pollutant Emissions

In recent years, the global demand for energy has been continuously increasing. Biodiesel as a replacement for fossil fuels holds strategic importance for sustainable economic development, mitigating the environmental impact, and managing air pollution. The utilization of second-generation biodiesel has garnered significant research interest due to its physical and chemical characteristics that are comparable to diesel, its elevated cetane number, and its reduced viscosity. This study will transform the TBD234v6 fuel system, transforming the original diesel fuel system into a second-generation biodiesel/diesel hybrid fuel system. This study examined the impacts of second-generation biodiesel on combustion, performance, and emissions in diesel engines, as well as the influence of the deoxygenation rate on second-generation biodiesel. Grey decision-making was used to determine the optimal mixing ratio and deoxygenation rate. The results indicated that the optimal blend comprises 10% second-generation biodiesel and 90% diesel fuel. In dual-fuel mode at this blend ratio, there is a 3% increase in maximum pressure compared to running on pure diesel. Moreover, the fuel consumption rate decreases by approximately 5.6%. Nitrogen oxide (NOx) and soot emissions decreased by 4.7% and 4.9%, respectively.

Numerical Investigation of Combustion and Emission Characteristics of the Single-Cylinder Diesel Engine Fueled with Diesel-Ammonia Mixture

This study proposes a dual-fuel approach combining diesel and ammonia in a single-cylinder compression ignition engine to reduce harmful emissions from internal combustion. Diesel is directly injected into the combustion chamber, while ammonia is introduced through the intake manifold with intake air. In this study, injection timing and the percentage of ammonia energy fraction was varied. A computational fluid dynamics (CFD) model simulates the combustion and emission processes to assess the impact of varying diesel injection timings and ammonia energy contributions. Findings indicate that as ammonia content increases, the engine experiences reductions in peak in-cylinder pressure, temperature, heat release rate, as well as overall efficiency and power output. Emission results suggest that greater ammonia usage leads to a reduction in soot, carbon monoxide, carbon dioxide, and unburned hydrocarbons, though a slight increase in nitrogen oxides emissions is observed. This analysis supports ammonia’s potential as a low-emission alternative fuel in future compression ignition engines.

Diagnosing the Process of Forming Biofuel Combustion Mixtures in Diesel Engines by a Program to Compute Spray Volume

A diesel engine's injection and combustion mixture formation process are essential; it determines the engine's economic, technical, and environmental criteria. When the engine uses biofuel, fuel parameters such as viscosity, density, and surface tension affect the above process. Each engine using a specific fuel type will have to adjust injection parameters such as injection pressure and timing to ensure the injection process and formation of a homogeneous air-fuel mixture. Therefore, through the spray structure, it is possible to diagnose the process of combustion mixture formation, thereby making adjustments to the fuel injection system that will improve engine performance and reduce emissions of toxic exhaust gases. In this study, the article presents the content of building a program to compute spray volume using Matlab software. Through the spray volume, quickly diagnose the process of forming the biofuel-air mixture in the diesel engine combustion chamber, thereby determining the appropriate fuel injection system adjustment. Results of simulation and experimental research on 4CHE Yanmar engines installed on fishing vessels with fuel types DO, B5, B10, and B15 show that the B15 fuel mixture when used for the engine needs to be increased injection pressure is about 10% higher than DO fuel injection pressure.

NUMERICAL INVESTIGATION OF WATER ADDITION INTO INTAKE AIR IN MODERN AUTOMOBILES DIESEL ENGINES

In the present study, the effects of water addition into intake air (WAIA) on combustion, engine performance, and NO emission in diesel engines were investigated numerically. Here, Ferguson's thermodynamic-based zero-dimensional single-zone cycle model was used and improved with some new approaches for neat diesel fuel (NDF) and WAIA. After controlling the model's accuracy for NDF and WAIA, the effects of WAIA were first investigated in the Renault K9K diesel engine. For (5 and 7.5)% water ratios (WRs), effective power decreased by 4.26% and 7.37%, brake specific fuel consumption (BSFC) increased by 6.95% and 10.56%, and NO emission reduced by 12.43% and 16.39%, respectively. In the second application, the effects of (3, 6, and 9)% WRs on combustion, engine performance, and NO emission in the Renault M9R type diesel engine were investigated at 4000 rpm by using this developed model. For (3, 6, and 9)% WRs, BSFC increased by 0.97%, 3.39%, and 8.25%, and NO emission decreased by 10.31%, 17.66%, and 34.20%, respectively. For (3 and 6)% WRs effective power increased, and NO emission decreased significantly without considerable deterioration in the BSFC at 4000 rpm. Cylinder pressure values and heat release rate increased for (3 and 6)% WRs and decreased for 9% WR.

Enriching various biodiesel feedstocks with Al2O3 nanoparticles in diesel engines: Performance, emissions, and exergy analysis

The inherent drawbacks of biodiesel, particularly its poor performance in cold climates, necessitate the use of nano-additives to improve its cold flow properties such as the cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). In this study, transesterification was employed to produce methyl esters from waste cooking oil, corn oil, and jatropha oil. These biodiesels were blended with diesel fuel at a 20% biodiesel and 80% diesel volume ratio and enriched with nano-Al2O3 at concentrations of 25, 50, and 100 mg/L. The aim of this study is to evaluate the impact of nano-Al2O3 on engine combustion, performance, exergy, and emissions of diesel engines using different biodiesel feedstocks. The addition of nano-Al2O3 to methyl ester mixtures (JB20A100, CB20A100, and WB20A100) resulted in enhancements in thermal efficiency by 8%, 11%, and 13%, respectively. CO emissions were reduced by 12%, 17%, and 22% for jatropha, corn, and waste cooking oil blends, respectively, with 100 ppm alumina. This reduction in CO emissions can be linked to the enhanced oxidation process facilitated by the high surface area of the nanoparticles, which act as catalysts, promoting more complete combustion. Similarly, UHC emissions decreased by 14%, 18%, and 23%, and smoke concentrations were significantly reduced by 14%, 17%, and 24% across the biodiesel blends. However, the introduction of alumina led to the rise in NOx emissions by 9%, 15%, and 19% for JB20A100, CB20A100, and WB20A100, respectively. The study also revealed increases in cylinder pressure by 2%, 4%, and 8%, and maximum heat release rates by 3%, 6%, and 10% for JB20, CB20, and WB20, respectively, upon the incorporation of 100 ppm Al2O3. Exergetic efficiencies improved by 6%, 17%, and 23% for JB20A100, CB20A100, and WB20A100, respectively, and the sustainability index showed enhancements of 2%, 4%, and 7%. Among the tested blends, WB20 with 100 ppm of nano-Al2O3 demonstrated the most promising results, significantly improving engine exergy, combustion, and performance while mitigating emissions to acceptable levels. This study underscores the potential of nano-additives to advance the sustainability and efficiency of diesel engine operations, particularly in cold climate.

Operation parameters investigation on combustion and emission of a non-road diesel engine based on orthogonal experiment design at different altitudes

For improving the combustion and emission performance of engines operating at high altitude regions, a two OED optimization method was proposed. The influence of each factor on the target was analyzed and discussed through a primary OED. Based on the primary OED test, factors with less influence were excluded to reduce factors in the secondary OED test. The results showed that low intake pressure led to poor spray mixing, prolonged ignition delay, and incomplete combustion, resulting in deteriorated power output, fuel economy, and emission characteristics. After two OED optimizations, The NOx emissions increased significantly by 40.5 % and 122.5 % in the first and second optimization, respectively, however, the ISFC decreased by 13.4 % and 25.2 %, and CO decreased by 13.0 % and 25.2 % in the first and second optimization, respectively, as well as ultra-low carbon smoke emissions was achieved. The related theories and methods' advantage can be extended to engineering applications and has good practical value.

Prediction and Simulation of Biodiesel Combustion in Diesel Engines: Evaluating Physicochemical Properties, Performance, and Emissions

Environmental and energy sustainability concerns have catalyzed a global transition toward renewable biofuel alternatives. Among these, biodiesel stands out as a promising substitute for conventional diesel in compression-ignition engines, providing compatibility without requiring modifications to engine design. A comprehensive understanding of biodiesel’s physical properties is crucial for accurately modeling fuel spray, atomization, combustion, and emissions in diesel engines. This study focuses on predicting the physical properties of PODL20 and EB100, including liquid viscosity, density, vapor pressure, latent heat of vaporization, thermal conductivity, gas diffusion coefficients, and surface tension, all integrated into the CONVERGE CFD fuel library for improved combustion simulations. Subsequently, numerical simulations were conducted using the predicted properties of the biodiesels, validated by experimental in-cylinder pressure data. The prediction models demonstrated excellent alignment with the experimental results, confirming their accuracy in simulating spray dynamics, combustion processes, turbulence, ignition, and emissions. Notably, significant improvements in key combustion parameters, such as cylinder pressure and heat release rate, were recorded with the use of biodiesels. Specifically, the heat release rates for PODL20 and EB100 reached 165.74 J/CA and 140.08 J/CA, respectively, compared to 60.2 J/CA for conventional diesel fuel. Furthermore, when evaluating both soot and NOx emissions, EB100 displayed a more balanced performance, achieving a significant reduction in soot emissions of 34.21% alongside a moderate increase in NOx emissions of 45.5% compared to diesel fuel. In comparison to PODL20, reductions of 20.4% in soot emissions and 3% in NOx emissions were also noted.