Performance Characteristics Of Engine Research Articles

Optimization and experimental investigation of compression ignition diesel engine performance and emission characteristics with Gulmohar biodiesel / diesel blends using Response Surface Methodology

Abstract This research focuses on biodiesel production from Gulmohar seeds using the transesterification method, with methanol as a catalyst at a 75% yield of Gulmohar oil biodiesel. Further, the biodiesel mixed with diesel at various blend ratios such as B20, B30, B40 and B50 and physicochemical characteristics are examined. The experimental investigation of performance and emission characteristics on single cylinder diesel engine using gulmohar biodiesel and diesel blends and compare the results with those from diesel. According to the findings, B20 blend emission characteristics and performance are very similar to the diesel fuel trend. Under full load, the Brake Specific Fuel Consumption (0.305 kg/kW.h) and Brake thermal efficiency (26.02%) for the B20 blend, which is closer to diesel and variations are 4.81% and 8.1%, respectively. Throughout the experiment, HC, CO, and smoke emission parameters were either less or equal for gulmohar biodiesel and its blends compared to diesel. However, the NOx emission of the biodiesel blends is 2 to 12% higher than diesel, but B20 has a 2.35% higher and lowest value among all the other blends. In addition, a central composite design (CCD) model using Response Surface Methodology (RSM) will be created, and the outcomes of a Compression Ignition (CI) engine will be optimized. Both analyses concluded that B20 is the most optimal blend among other blends and serves as a substitute for diesel.

Exploring Hydrogen–Diesel Dual Fuel Combustion in a Light-Duty Engine: A Numerical Investigation

Dual fuel combustion has gained attention as a cost-effective solution for reducing the pollutant emissions of internal combustion engines. The typical approach is combining a conventional high-reactivity fossil fuel (diesel fuel) with a sustainable low-reactivity fuel, such as bio-methane, ethanol, or green hydrogen. The last one is particularly interesting, as in theory it produces only water and NOx when it burns. However, integrating hydrogen into stock diesel engines is far from trivial due to a number of theoretical and practical challenges, mainly related to the control of combustion at different loads and speeds. The use of 3D-CFD simulation, supported by experimental data, appears to be the most effective way to address these issues. This study investigates the hydrogen-diesel dual fuel concept implemented with minimum modifications in a light-duty diesel engine (2.8 L, 4-cylinder, direct injection with common rail), considering two operating points representing typical partial and full load conditions for a light commercial vehicle or an industrial engine. The numerical analysis explores the effects of progressively replacing diesel fuel with hydrogen, up to 80% of the total energy input. The goal is to assess how this substitution affects engine performance and combustion characteristics. The results show that a moderate hydrogen substitution improves brake thermal efficiency, while higher substitution rates present quite a severe challenge. To address these issues, the diesel fuel injection strategy is optimized under dual fuel operation. The research findings are promising, but they also indicate that further investigations are needed at high hydrogen substitution rates in order to exploit the potential of the concept.

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 and 100 mg/L 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 465oC respectively. Similarly, reduced emission of CO, NOx, HC and smoke opacity was observed in the CeO2 added blends particularly at 100 mg/L. It was concluded that among all blends prepared, the D70:WPO30 with 100 mg/L of CeO2 showed improved combustion, performance and emission characteristics in proposed diesel engine.

Prediction of Efficiency, Performance, and Emissions Based on a Validated Simulation Model in Hydrogen–Gasoline Dual-Fuel Internal Combustion Engines

This study explores the performance and emissions characteristics of a dual-fuel internal combustion engine operating on a blend of hydrogen and gasoline. This research began with a baseline simulation of a conventional gasoline engine, which was subsequently validated through experimental testing on an AVL testbed. The simulation results closely matched the testbed data, confirming the accuracy of the model, with deviations within 5%. Building on this validated model, a hydrogen–gasoline dual-fuel engine simulation was developed. The predictive simulation revealed an approximately 5% increase in overall engine efficiency at the optimal operating point, primarily due to hydrogen’s combustion properties. Additionally, the injected gasoline mass and CO2 emissions were reduced by around 30% across the RPM range. However, the introduction of hydrogen also resulted in a slight reduction (~10%) in torque, attributed to the lower volumetric efficiency caused by hydrogen displacing intake air. While CO emissions were significantly reduced, NOx emissions nearly doubled due to the higher combustion temperatures associated with hydrogen. This research demonstrates the potential of hydrogen–gasoline dual-fuel systems in reducing carbon emissions, while highlighting the need for further optimization to balance performance with environmental impact.

Multi‐aspect assessment and multi‐objective optimization of preheated tallow biodiesel‐diesel blend as alternate fuel in CI engine

AbstractThis study meticulously examined the impact of preheated tallow biodiesel on the performance and emission characteristics of a diesel engine. Employing a single‐cylinder, water‐cooled diesel engine configured with exhaust gas recirculation in this investigation, exhaust gas temperature (EGT) could be used to preheat the biodiesel, reducing its viscosity and density. This improvement in viscosity and density could enhance the injection process, which is often hindered by the higher density and viscosity of biodiesel compared with diesel fuel. The investigation achieved a peak preheat temperature of 70°C for the biodiesel, leading to notable improvements in brake thermal efficiency and brake power, particularly under high‐load conditions. A significant reduction in emissions was observed, with hydrocarbon and carbon monoxide levels decreasing by 46.87% and 50%, respectively, when using preheated biodiesel. To refine the engine's performance further, this study utilized response surface methodology (RSM) for the optimization of operational parameters, including injection timing, engine load, and biodiesel preheat temperatures. Optimal conditions were identified at an injection timing of 21° before top dead centre, a preheat temperature of 64°C, and an engine load of 45.45% for which output response was 18.68% brake thermal efficiency, 307°C EGT, 0.0247% vol. CO, 15.32 ppm hydrocarbons, and 131.37 ppm nitrogen oxides (NOx). The successful implementation of preheated tallow biodiesel signifies a crucial step forward in the pursuit of a more sustainable and efficient transportation industry. This advancement holds the promise of reducing reliance on traditional fossil fuels, thereby contributing to the global efforts towards achieving a more environmentally friendly energy landscape.

Effects of isopropanol-butanol-ethanol on the performance, combustion and emission characteristics of a diesel-methanol dual-fuel engine

Both diesel-methanol dual-fuel (DMDF) combustion and the addition of isopropanol-butanol-methanol (IBE) into diesel are capable of reducing the fossil fuel usage and soot emissions of diesel engines, but few of studies focused on combining the advantages of these two methods. Thereby, diesel containing 10 %, 20 % and 30 % of IBE by volume were utilized as pilot fuel in this study to investigate how the addition of IBE into diesel affects the performance, combustion and emissions of the DMDF engine. Experiments were performed at the engine load of 20 %, 40 % and 60 % with the engine speed fixed at 1400r/min. The results show that at most test conditions, the brake thermal efficiency of the DMDF engine only suffers a slightly drop while the soot emissions greatly reduce when IBE is blended into the pilot fuel diesel. Moreover, the deterioration of CO, HC and NOx emissions of DMDF engine can be significantly improved by blending no more than 20 % vol. IBE into the pilot fuel diesel. Additionally, with the volume ratio of IBE into the pilot fuel diesel increases to 30 %, the soot emissions of the DMDF engine can be further reduced at the costs of engine performance deteriorates and CO, HC, NOx emissions increase. Although the deterioration of the engine performance caused by the addition of IBE into the pilot fuel diesel can be mitigated by increasing the methanol flow rate, NOx emissions increase significantly.

Effect of fuel characteristics coupled with injection parameters on oil–gas mixing and combustion processes in diesel engines

The physicochemical properties of fuels are critical determinants of the in-cylinder processes, overall performance, and emission characteristics of internal combustion engines. The distinctive characteristics of various fuels during atomization, evaporation, oil–gas mixing, ignition, and combustion phases play a decisive role in determining the combustion efficiency, thermal efficiency, and formation of pollutants. This study conducts a comprehensive comparative analysis of the physical and chemical properties of five distinct fuels, focusing on their interactions with the injection parameters. This investigation delineates the influence of these properties on the spray breakup dynamics and subsequent combustion processes. Results demonstrate that while the fuels exhibit varying sensitivities to injection parameters, optimal combustion performance is consistently achieved when the injection timing is set at 22° Before the Top Dead Center(BTDC), the nozzle orifice diameter is 0.32 mm, and the beam angle is maintained at 160°. This analysis provides novel insights into the complex coupling effects of fuel properties and injection strategies on in-cylinder processes, thereby contributing to the design and development of high-efficiency, low-emission internal combustion engines.

Enhancing Jatropha oil biodiesel by using Citrus Limetta peels as a biocatalyst: A sustainable way to reduce emissions and enhance the efficiency of CI engine

Biodiesel has become one of the promising alternative fuel resources for petro-diesel. Biodiesel is obtained by mixing oil and alcohol through transesterification reaction. A catalyst (base or acid) is typically added to accelerate the transesterification reaction and yield the maximum biodiesel production. The use of the traditional catalyst has problems like catalyst separation, soap formation, high reaction time, more energy consumption and environmental pollution. Literature shows that the addition of a catalyst from organic sources can overcome these problems. Biocatalysts were produced from different bio-waste like animal bones, plant leaves, fruit and vegetable peels, but there is no work found on the effects of Citrus Limetta peel waste for the biodiesel production. In this work, the feasibility of using Citrus Limetta peel ashes as an eco-friendly biocatalyst was investigated for the biodiesel production from Jatropha oil. The biocatalyst was obtained from Citrus Limetta peel waste after drying, pulverizing and calcination. XRD, SEM and EDX were used for the characterization of the biocatalyst. The biodiesel was tested for conformance with Euro standards. Then, three biodiesel blends (JT90, JT80 and JT70 with 10, 20 and 30 % biodiesel) were tested for determining the engine performance and emission characteristics in a Kirloskar 4-stroke CI diesel engine. SEM and EDX indicated a substantial concentration of potassium (26.8 %) and calcium (71.59 %) in the biocatalyst. The maximum biodiesel yield was achieved with 2 wt% biocatalyst, 15:1 Jatropha-to-methanol molar ratio, 60 °C reaction temperature and 1 h reaction time. Engine performance study showed that the JT80 blend demonstrated a BTE improvement of 1.2 % with a significant BSFC reduction of 11 % when subjected to full load conditions, surpassing that of pure diesel. Emissions study revealed that the JT80 blend demonstrated a substantial decrease in emissions compared to pure diesel. Specifically, there was a noteworthy 10.3 % reduction of carbon monoxide (CO), 14 % of carbon dioxide (CO2), 11 % of unburnt hydrocarbon (HC) and 3 % of nitrogen oxides (NOX), but with an increase of 2 % in smoke emissions.

Experimental investigation on diesel engine performance and emission characteristics using waste cooking oil blended with diesel as biodiesel fuel

Biodiesel production from waste cooking oil is a potential feedstock to alternative fuel sources. Produced alternative fuel sources were to have a strong emphasis on energy efficiency to substitute the declining world supply of fossil fuels while also improving emission characteristics in diesel engine applications. The development of industrialization and mechanization causes increased fossil fuel consumption and its usage. This study aimed at an experimental investigation of biodiesel blended fuel combustion efficiency for single-cylinder diesel engines under varying engine loads at constant engine speed 1500 rpm. The transesterification process was used to produce biodiesel from waste cooking oil using NaOH as catalysts. Biodiesel reaction takes place with oil to methanol ratio of 6:1 at 60 °C reaction temperature for 90 min with 600 rpm stirring speed while 90% yield gained. Eight sample biodiesel blends were prepared with percentage value B5%, B10%, B15%, B20%, B25%, B30%, B35%, B40% v/v and B100% to investigate the effect of biodiesels on engine performances. The experimental result reveals that the mixed biodiesel blends have lower average value in terms of brake torque, brake power, and brake thermal efficiency than diesel fuels as a percentage of 16.79%, 4.08%, and 27.9% respectively. In addition, the average BSFC of biodiesel blends was increased by 4.8% than baseline diesel fuel. Related to exhaust gases emission test results were shows that the average CO and HC emissions decreased by 52.2% and 60% with increasing loads and blends and the increment of CO2 and NOx by 28.1% and 45.4% respectively than baseline fuel with increasing blends and loads. Biodiesel derived from waste cooking oil was less costly and environmentally friendly and viable to substitute petro-diesel.

Production of oxy-hydrogen with an alkaline electrolyzer, and its impacts on engine behaviors fuelled with diesel/waste fish biodiesel mixtures supported by graphene-added nanofuels

Because of the high viscosity, low calorific value, atomization, and vaporization problems of biodiesel, addition of nano additives with oxyhydrogen is encouraged to improve engine combustion and emissions. Waste fish methyl ester was blended with diesel oil in 20%, and then nano graphene was added to diesel-biodiesel mixtures at doses of 25, 50, and 100 mg/L. An alkaline electrolyzer was employed to generate oxyhydrogen gas at a rate of 0.5 liters per minute through water electrolysis. At 3000 rpm rated speed and engine load range from 25 to 100% with the interval of 25% were investigated. Mixtures of graphene in methyl ester combinations have increased the thermal efficiency of biodiesel blend by 11%, 13%, and 15%, respectively, when supplemented with HHO. The addition of 25, 50, and 100 ppm of graphene to the methyl ester was mixed along with oxyhydrogen, resulting in notable reductions of CO emissions by 18%, 22%, and 25% for WF20. Significant decreases in HC emissions by 29%, 32%, and 38%, accompanied by noticeable declines in smoke concentrations of 25%, 28%, and 33% for WF20G25 + HHO, WF20G50 + HHO, and WF20G100 + HHO were shown. Moreover, NOx emissions experienced reductions of 20%, 24%, and 29% when HHO was added to methyl ester blends containing 25, 50%, and 100 ppm of graphene, respectively. Incorporating biodiesel from waste fish oil, enriched with 100 ppm graphene with HHO shows potential for lowering exhaust emissions, and enhancing engine performance and combustion characteristics, particularly for the commonly used biodiesel with poor fuel properties.

Enhancing Combustion Efficiency: Utilizing Graphene Oxide Nanofluids as Fuel Additives with Tomato Oil Methyl Ester in CI Engines

The research aims to conduct a thorough examination of the combustion, injection, performance, and emission characteristics of a diesel engine below different engine loads, as well as the synthesis of graphene oxide (GO) nano fuels and their utilization in combination with Tomato Oil methyl ester (TOME) and diesel fuel blend. The graphene oxide, plays a vital role in the pre-mixed combustion phase of diesel engines. Addition of graphene oxide nano fuels enhances the high-pressure combustion stage, resulting in increased maximum pressure and heat release rate. TOME (B20GO75) and TOME (B20GO100) exhibit comparable heat release rate to diesel due to improved fuel characteristics and quicker ignition delay duration. While TOME (B20) shows a slight decrease in (BTE) compared to diesel, the addition of graphene oxide improves BTE, with TOME (B20GO50) displaying the highest BTE at full load, indicating enhanced combustion efficiency. Moreover, graphene oxide addition leads to a reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions, with emissions decreasing as the concentration of graphene oxide increases. However, NoX emissions initially decrease with TOME (B20) compared to diesel but increase with higher graphene oxide concentration. Smoke emissions increase with TOME (B20) but decrease with higher graphene oxide dosages. Overall, the incorporation of graphene oxide nano fuels into Tomato Oil methyl ester blends demonstrates potential for improving engine performance and reducing emissions.

Investigation into the impact of acetylene on performance and emission characteristics of a compression ignition engine using a blended biodiesel of ethanol and tamanu oil.

Due to the significant increase in transportation, traditional fossil fuels utilised in internal combustion engines will only be accessible for a limited duration. Additionally, the harmful pollutants produced by these fuels, including CO, NOx, unburned hydrocarbons, smoke, and a small amount of particulate matter, have a severe negative impact on the environment. Although biodiesel proves efficient without necessitating engine modifications, its performance is hindered by its higher viscosity. Consequently, this research aims to enhance performance by introducing acetylene alongside tamanu methyl ester (biodiesel); however, this approach results in elevated NOx levels. To mitigate NOx emissions, a combination of ethanol and biodiesel is employed. This study investigates the performance and emission attributes of Acetylene + TME90E10 as the fuel. The combustion pressure and heat release rate of TME90E10 with 6 lpm, improved by 5.41% and 9.1% than diesel. When compared to regular diesel fuel, the introduction of 6l per minute of acetylene with TME90E10 yields a substantial 24.4% decrease in hydrocarbon (HC) emissions. Furthermore, employing TME90E10 at the same acetylene flow rate demonstrates the lowest carbon monoxide (CO) emissions, registering at 0.07%, in contrast to the 0.13% emissions observed throughout the exhaust cycle when using pure diesel fuel.

Experimental study of ammonia energy ratio on combustion and emissions from ammonia-gasoline dual-fuel engine at various load conditions

Achieving carbon neutrality necessitates the adoption of zero-carbon fuels in engine applications, with ammonia emerging as an up-and-coming candidate due to its favorable safety profile and advantages in storage and transportation. This study experimentally investigated the feasibility of an ammonia-gasoline dual-fuel (AGDF) engine to achieve comparable power output and satisfactory carbon reduction without changing the main structural parameters of the engine. A four-cylinder, naturally aspirated, spark ignition engine was used to investigate the impact of ammonia energy ratio (AER), engine base torque and engine speed on the engine performance, combustion evolution and emission characteristics. The findings reveal that the brake thermal efficiency (BTE) in AGDF mode is lower than in gasoline-only mode, primarily due to the reduced combustion activity. However, this efficiency decline becomes noticeable only when the AER exceeds 15 %. Additionally, at high AERs and high engine base torques, the delayed effect of ammonia fuel on the main combustion period results in a double-peak pattern, which limits the energy output but presents opportunities for phase optimization. The study also examined three incomplete combustion emissions, each exhibiting distinct behaviors. Except for ammonia slip, adding ammonia fuel does not significantly affect carbon monoxide (CO) and unburned hydrocarbons (UHC) emissions, particularly at AERs below 25 %. Nevertheless, nitrogen oxide (NOx) emissions under AGDF combustion are significantly higher than under gasoline alone in most instances. Crucially, the study demonstrates the carbon reduction potential of ammonia fuel across different engine loads, with a maximum carbon dioxide (CO2) reduction of 46.8 % at a 35 % AER. It is anticipated that further optimization of the combustion phase will improve the capability for carbon reduction.

Performance analysis of dual-fuel engines using acetylene and microalgae biodiesel: The role of fuel injection timing

This study evaluates the impact of varying fuel injection timing (FIT) and dual-fuel modes on the performance and emissions of a compression ignition (CI) engine under different load conditions. The biodiesel used was derived from Chlorella protothecoides microalgae through a two-step transesterification process, and its elemental composition was characterized using gas chromatography-mass spectrometry (GC-MS). Acetylene gas was introduced into the engine intake manifold at a rate of 3 L per minute (LPM), while a blend of 20 % methyl ester from Chlorella protothecoides (B20 MEOA) served as the primary injected fuel. To predict engine performance and emission characteristics, advanced machine learning models were employed and evaluated using four statistical criteria, including R-squared, mean absolute error (MAE), and mean squared error (MSE). Experimental results indicated that the optimal configuration involved a dual-fuel mode combining B20 MEOA with acetylene gas and an advanced FIT of 25° before top dead center (bTDC). Performance analysis revealed that under all load conditions, the specific fuel consumption (SFC) decreased by 7.3 %, while brake thermal efficiency (BTE) increased by 1.6 % compared to conventional diesel. Emission testing showed a 7.6 % rise in nitrogen oxide emissions, alongside significant reductions in unburned hydrocarbons (12.5 %), carbon monoxide (25.6 %), and smoke intensity (7.5 %) relative to standard diesel operation. Optimization of the engine parameters ensured that key metrics, such as brake power (BP) and brake-specific fuel consumption (BSFC), remained within acceptable limits. The random forest model outperformed other machine learning models, demonstrating superior accuracy in predicting performance and emissions across all statistical measures. This study underscores the potential of combining advanced biodiesel blends with optimized FIT strategies to improve engine efficiency and emissions control, offering a promising approach for sustainable dual-fuel engine operations.

Effect of hybrid nanoparticles dispersed ternary fuel blend on diesel engine performance and emissions: Experimental and Taguchi-Grey relation study

The present study deals with the influence of hybrid nanoparticles dispersed in ternary fuel mixtures on the evaluation of the performance and emission characteristics of a single cylinder diesel engine. The fuel blend consists of 70 % diesel, 20 % Madhuca longifolia biodiesel, and 10 % ethanol (by volume). The hybrid nanoparticles of ferric chloride (FeCl3) and graphene nanoparticles were then added to this ternary fuel mixture in different proportions, namely 50 mg/L and 75 mg/L, together with the surfactant and the dispersant in a ratio of 1:1. Moreover, the experiments were conducted on a diesel engine to evaluate the performance and emission parameters by varying different fuel samples, different loads (3, 6, 9, and 12 kgf) and injection pressures (i.e. 200, 225,and 250 bar). In addition, the Taguchi-Grey relation analysis was used for optimization, and the input parameters are fuel samples, loads and injection pressures. Experimental performance metrics, including brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE), were improved when hybrid nanoparticles were added to the ternary fuel blend compared to diesel. At the same time, smoke opacity, nitrogen oxides (NOx), unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions were reduced. Increasing the injection pressure also led to positive results, apart from NOx. Both performance and emissions were better for hybrid nanofuel based on surfactants and dispersants than for the base fuel, and it performed better of all dispersant-added nanofuels. The better results were obtained with D70B20E10NPs75QPAN75 mg/L than with the other fuel samples. The maximum BTE and lowest BSFC are 33.26 % and 0.206 kg/kWh, while the minimized CO, UHC, NOx and smoke values at full load are 0.019 %, 21 ppm, 833 ppm and 36.25 %, respectively, at full load and injection pressure of 250 bar By combining experimental investigations with the Taguchi -Grey method, a comprehensive and rapid assessment of the effects on the performance and emission characteristics of diesel engines was achieved.

Impact on Green Synthesised Al2O3 Nanoparticles on Performance and Emission Properties as Biodiesel operated diesel engine

<p style="text-align:justify;"><span style="font-family:"Times New Roman","serif";font-size:12pt;line-height:150%;">Global warming and pollution are two of the numerous causes of environmental issues due to industrial wastes and greenhouse gases. As a result, efforts are being made to limit emissions in order to mitigate these issues and reduce pollution. Given that fuel supplies are running low, biodiesel is one of the best alternatives to diesel fuel. One of the main obstacles to biodiesel's commercialization is its higher cost than diesel. One of the more superior substitute fuels for diesel is biodiesel, which is a fuel with great potential. When combined with 20% commercial diesel (B20), the resulting biodiesel is known as Pongamia. Improving engine performance and combustion characteristics while decreasing atmospheric NOX, CO, and HC exhaust emissions are the primary goals of this research. In comparison to neat diesel, BSFC and BTE were found to have increased by 12.27% and 15.34% respectively, while NOx, CO, and HC concentrations were decreased by 15.46%, 54%, 7.30%, and 25.67% respectively. Biodiesel mixed with Al<sub>2</sub>O<sub>3</sub> nano additive significantly improves the performance and combustion characteristics of diesel engines.</span></p>

Effect of engine parameters on the mixture distribution, performance and emission characteristics of a gasoline direct injection engine with baffles – A numerical analysis

Baffles inside the combustion chamber of internal combustion (IC) engines improve in-cylinder mixture distribution, performance, and emission characteristics. However, the effect of engine operating parameters on these aspects of the engine with baffles (EWB) remains underexplored. In this study, using computational fluid dynamics (CFD), the effects of fuel injection pressure (FIP), engine speed and load in a spray-guided, gasoline direct injection engine (GDI) are analysed and compared with the conventional engine. For the analysis, injection pressures of 30, 50, 80, and 120 bar; engine speeds of 1000, 2000, and 3000 rev/min.; and overall equivalence ratios of 0.7, 0.9, and 1.2 are considered, keeping the fuel injection timing constant. Results show that, EWB outperforms the conventional engine under various conditions considered. Also, it is found that the performance of EWB at an FIP of 30 bar is comparable to that of the base engine at an FIP of 80 bar. Additionally, the EWB exhibits better thermal efficiency across all the engine speeds and load conditions. Moreover, the HC and CO emissions of the EWB are found to be lower in most engine operating conditions. However, NOx emissions are marginally higher than those of the base engine.

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.

Experimental multiple parameters optimization of the injection strategies for a turbocharged direct injection hydrogen engine to achieve highly efficient and clean performance

Improving the brake thermal efficiency (BTE) and reducing NOx emissions are two main goals for hydrogen-powered internal combustion engines to achieve efficient and clean performance. This paper focuses on the multiple parameters optimization of injection and ignition both experimentally and numerically based on a 2.0L turbocharged direct injection hydrogen engine. Firstly, the effects of single and split injection on engine performance, in-cylinder mixing and combustion characteristics are investigated. Secondly, the single-factor effect of split injection parameters and spark timing on engine performance are obtained with different engine speeds. Significant interaction effects are detected between these factors. Thus, a multi-parameter optimization is conducted based on the response surface methodology method to analyze the co-relationship of factors (split injection control parameters and ignition) on responses (BTE, NOx emissions, and knock intensity) at high-load. Finally, a maximum BTE of 43.03 % and a reduction in NOx emissions by 71.19 % are achieved with the help of model prediction at 2500 rpm and a load of 1.40 MPa. Further optimization of other engine speeds is conducted, and the boundary of high-efficiency region (BTE>40 %) covers over 50 % of the load map after optimization. These results can provide valuable support for the performance improvement of efficiency and clean hydrogen engines.

Recycling waste tires into sustainable biofuel for replacing petroleum fuel in diesel engines using nanoparticles and biohydrogen.

In this paper, the production of pyrolyzed oil in lab scale plant and its possible use in variable speed diesel engine with nanoparticle and secondary fuel oxy-hydrogen gas is investigated. The pyrolyzed oil is produced from waste tires in lab scale plant, and after its distillation, it is blended with neat diesel in the proportion of 20:80 (TDF). The different testing fuels are prepared by mixing nanoparticle CeO2 (NP) at the concentrations 50ppm and 100ppm with blended fuel (named as TDF-NP50 and TDF-NP100). While in the testing phase, the HHO gas is supplied through specially designed venturi at fixed flow rate (fuel designated as TDF-NP50-HHO and TDF-NP100-HHO). The focus of current investigation is to investigate the combined impact of inducting HHO with nanoparticle mixed pyrolyzed blends on engine performance and emissions characteristics. The pyrolyzed blended fuel deteriorate the BTE, BSFC, emissions of HC and NOx while improves the CO emission. The improvement in all the characteristics can be achieved by introducing CeO2 nanoparticle at 50ppm and 100ppm which improves BTE by 15-24%, BSFC by 2.2-4.2%, HC by 8-18%, CO by 7-12%, and NOx by 7-16%. The further improvement can be achieved by inducting HHO gas, which are BTE 11%, BSFC 5-8%, HC 15%, and CO 13-16%. However, the NOx emission is increased by 14-17%. Hence, the waste tire-derived pyrolyzed oil along with green hydrogen and nanoparticles CeO2 can be used as a sustainable transportation fuel in existing CI engine.