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This study reports the impacts of dual fuel mixtures on the theoretical performance characteristics of a spark ignition engine (SIE). The effects of addition of liquefied hydrogen, methane, butane, propane (additive fuels) into gasoline, iso-octane, benzene, toluene, hexane, ethanol and methanol fuels (primary fuels) on the variation of power, indicated mean effective pressure (IMEP), thermal efficiency, exergy efficiency, were examined by using a combustion model. The fuel additives were ranged from 10 to 50% by mass. The results exhibited that the ratios of hydrogen, methane, butane, propane noticeably affect the performance of the engine. The maximum increase ratio of power is 82.59% with 50% of toluene ratio and its maximum decrease ratio is 10.84% with 50% of methanol ratio in hydrogen mixtures. The maximum increase ratio of thermal efficiency and exergy efficiency are observed as 26.75% and 32.23% with the combustion of benzene-hydrogen mixtures. The maximum decrease ratio of thermal efficiency is 29.71% with the combustion of 50% of methanol ratio and it is 21.95% for the exergy efficieny with the combustion of 50% of ethanol ratio in hydrogen mixtures. The power, IMEP, thermal efficiency and exergy efficiency of primary fuels demonstrate different variation characteristics with respect to type and ratio of additive fuels.

The increasing demands for fuel economy and emission reduction have led to the development of lean/diluted combustion strategies for modern Spark Ignition (SI) engines. The new generation of SI engines requires higher spark energy and a longer discharge duration to improve efficiency and reduce the backpressure. However, the increased spark energy gives negative impacts on the ignition system which results in deterioration of the spark plug. Therefore, a numerical model was used to estimate the spark energy of the ignition system based on the breakdown voltage. The trend of spark energy is then recognized by implementing the classification method. Significant features were identified from the Information Gain (IG) scoring of the statistical analysis.

The use of ethanol blend as an alternative source of fuel for developing clean and sustainable energy sources has grown considerably. In this study, the performance characteristics of an air-cooled, single-cylinder 4-stroke Spark Ignition (SI) engine (TD201) with a compression ratio of 8.5:1 was determined using gasoline and different blend ratios of ethanol and gasoline (E0, E2, E4, E6, E8, E10, and E12) at a varied engine speed of 2000rpm, 2200rpm, 2400rpm, 2600rpm and 2800rpm. The results revealed that as the ethanol content of the blend increases, the heating value decreases while octane value increases. The experimental results indicated that the brake torque, and power increase as the ethanol content in the blends increases. However, BSFC and exhaust temperature decreases as the ethanol content in the blends increases because of the oxygen enrichment. The emissions of unburned hydrocarbon and carbon monoxide reduce while carbon dioxide and ethanol content increases when compared with the reference fuel (E0).

To meet the stringent emission regulations and fuel economy demands of the spark ignition (SI) engine, more and more new technologies such as turbocharging, variable valve actuation (VVA), and exhaust gas recirculation (EGR) are being developed. For the turbocharged SI engine, the high boost pressure can lead to higher laminar combustion velocity with higher maximum burned gas temperature, which induces more emissions; it also carries a risk of serious knocking, which can not only deteriorate the brake-specific fuel consumption (BSFC) but also destroy the engine. As is well known, the dilution mixture gas methods, which include VVA and EGR, are effective techniques to advance the combustion phase and suppress knocking in the SI turbocharged engines. The effects of VVA and EGR rates on the BSFC and combustion characteristics of an SI engine were analyzed through 100 groups of engine experiments, and the quantitative analysis of the influence saliency of VVA and EGR rates has been introduced. Then, the optimal level of each factor was obtained by a comprehensive balance method. The results indicated that the EGR rate has the most significant influence on the BSFC and CA50. At the same time, the BSFC was only 211.7 g/kWh, which has been improved significantly, and CA50 was 12.55° CA ATDC, which effectively enhances the knock resistance when applying the optimization parameters.

Ethanol dual injection (DualEI) is a new technology to maximise the benefits of ethanol fuel to the spark-ignition engine. In this study, the combustion and emissions characteristics in a DualEI spark-ignition engine with a variation of the direct injection (DI) ratio and engine speed were experimentally investigated. The volume ratio of DI was varied from 0% (DI0%) to 100% (DI100%), and two engine speeds of 3500 and 4000 RPM were tested. The spark timing for maximum brake torque (MBT) was first determined, and then the results of the effect of DI ratio on the engine performance at the MBT conditions were discussed and analysed. The results showed that the MBT timing for the DI and spark timings were 330 and 30 CAD bTDC, respectively. At the MBT timing, the indicated mean effective pressure slightly increased from 0.47 to 0.50 MPa when the DI ratio increased from DI0% to DI100%. However, the maximum combustion pressure significantly decreased by 8.32%, and volumetric efficiency increased by 4.04%. This was attributed to the reduced combustion temperature due to the cooling effect of ethanol fuel enhanced by the DI strategy. The indicated specific carbon monoxide and hydrocarbons significantly increased due to poor mixture quality caused by fuel impingement associated with the overcooling effect. However, the indicated specific nitric oxides significantly decreased due to the temperature reduction inside the combustion chamber. Results showed the potential of DualEI to increase the compression ratio and consequently increase the engine thermal efficiency without the risk of engine knock.

The results of experimental studies of gasoline mixed with 10% bioethanol (E10), bioethanol mixed with 15% gasoline (E85), and hydrogen– oxygen gas (HHO) supplied as an additional fuel are presented in this paper. Research was carried out to determine whether E85 with hydrogen– oxygen gas is feasible for use as a replacement fuel. During the test, a port injection HR16DE spark ignition engine was used. Experiments were carried out at a constant engine speed (n = 2000 rpm), throttle opened at 15°, using a stoichiometric mixture λ = 1.0 and a lean mixture λ = 1.1. After determining brake torque, fuel consumption data, and energy performance, the results of various fuels were determined. It was found that the highest engine brake torque was developed using E85, but at the same time, fuel consumption increased. E85 yielded the best energy efficiency for a lean mixture (λ = 1.1). A small amount of HHO gas (~ 0.95% energy) yielded a small positive effect only on using E10 fuel at λ = 1.1.

Accurate predictions of low-temperature heat release (LTHR) are critical for modeling auto-ignition processes in internal combustion engines. While LTHR is typically obscured by deflagration, extremely late ignition phasing can lead to LTHR prior to the spark, a behavior known as pre-spark heat release (PSHR). In this research, PSHR in a boosted direct-injection spark-ignition engine was studied using 3-D computational fluid dynamics (CFD) and detailed chemical kinetics. The turbulent combustion was modeled via a hybrid approach that incorporates the G-equation model for tracking the turbulent flame front, and the well-stirred reactor model with detailed chemistry for assessing the low-temperature reactions in unburnt gas. Simulations were conducted using Co-Optima alkylate and E30 fuels at operating conditions characterized by different PSHR intensities. The predicted in-cylinder pressure and heat release rate were found to agree well with experiments. It was found the estimate of previous-cycle trapped residuals is of utmost importance for capturing PSHR correctly. A simulation best practice was developed which keeps the detailed chemistry solver active throughout the entire simulation, allowing to track the evolution of intermediate species from one cycle to the next. Following the validation, the dynamics of PSHR were analyzed in detail employing the pressure-temperature (P-T) trajectory framework. It was shown that PSHR correlated with the first-stage ignition delay of the fuel, hence showing close relation to the in-cylinder P-T trajectory and the chemical kinetics. Besides, it was indicated that LTHR is a self-limiting process that has the effect of attenuating the thermal stratification in the combustion chamber. Furthermore, it was observed the occurrence of PSHR caused the P-T trajectory of end-gas to overlap with the negative temperature coefficient region of the fuel’s ignition-delay maps. This effect was more significant in the fuel-rich regions where engine knock tendency would be generally higher, with potential implications on knock control and mitigation.

A shift toward a circular and [Formula: see text]-neutral world is required, in which rapid defossilization and lower emissions are realized. A promising alternative fuel that has gained traction is methanol, thanks to its favorable and clean-burning fuel properties as well as its ability to be produced in a carbon-neutral process. Especially methanol’s high knock resistance and its combustion stability offer the opportunity to operate an engine at both a high compression ratio and a high excess air dilution. Although methanol has been investigated in series-production engines for passenger car applications, there is a lack of investigations on a dedicated engine that can operate at methanol’s knock limit. In this paper, methanol’s knock limitation is experimentally assessed by applying high compression ratios to a direct injection spark-ignition single-cylinder research engine. To that end, four compression ratios were investigated: 10.8, 15.0, 17.7, and 20.6. With compression ratios of 15.0 and 17.7, the lean-limit was increased to excess air ratios of 2.0 and 2.1, respectively, compared to 1.7 at a compression ratio of 10.8. For the highest compression ratio of 20.6, the maximum lean burn limit was increased to an excess air ratio of 1.9 due to achieving the maximum cylinder pressure limit. Despite the minor increase in lean-limit, a maximum indicated efficiency of 48.7% was achieved with the highest compression ratio of 20.6. However, even at this high compression ratio, methanol did not show a knock limitation. The investigations in this work provide profound knowledge for future engine investigations with methanol.

The main objective of this research is to generate the hydrogen gas as a fuel and part of hydroxy gas (HHO) from the drinking water (H2O) using electrolyzing method with a different electrolytes such as sodium hydroxide (NaOH), sodium carbonate (Na2CO3), and Vinegar in HHO generator for best results, the practical examinations were done by a generator that designed and built for this purpose using plate electrodes, with a rechargeable 12-volt battery and the produced gas was measured at each case and used as a fuel for operating a small single-cylinder spark-ignition engine (Honda G 200) with taking into account the safety precautions. The results show that increasing the ratio of (NaOH) grams/liter of H2O increases the gas production, while the other two electrolytes (Na2CO3 and vinegar) are not effecting too much, and using the mixing procedure (%) of the electrolytes (NaOH with Na2CO3) and (Na2CO3 with Vinegar), it is observed that the HHO generation noticeable increases with increasing the mixing ratio of the first mixture and not too much with the second.

Ionization current measured at the spark plug during combustion in spark ignition engines has often been proposed to determine the crank-angle at combustion pressure peak, namely the peak pressure angle, for the purpose of regulating spark timing to attain maximum brake torque (MBT). The proposal is based on the assumption that agreement exists between peak pressure angle and the angular position of the ionization current second peak, although no one has ever proved it by an appropriate statistical analysis. The aim of this work, for the first time and by rigorous statistical methods, is to prove the agreement between Peak Pressure Angle and Ionization Current Second Peak Angle (ICSPA), without which a MBT control via ICSPA would be ineffective. Our experimental database consisted of about 9000 pairs of Peak Pressure Angle and Ionization Current Second Peak Angle values corresponding to 90 different operating conditions of a spark ignition engine. A two-sample comparison was first carried out between mean values of Peak Pressure Angle and Ionization Current Second Peak Angle, which showed a statistically significant difference between them. Then Bland-Altman analysis (Lancet, 1986), widely known and used for checking agreement between two different measurement methods, was conducted. It demonstrated that under almost all the experimental operating conditions, there was no agreement between the Ionization Current Second Peak Angle and the Peak Pressure Angle.

A theoretical and experimental investigation on the performance and emission of spark ignition engine have been made using gasoline, alcohol and gasoline-alcohol mixture as fuels. A thermodynamic model has been developed with superimposed pseudo-kinetic NO and CO formation. This has been used to compute estimated performance and emission data for a spark ignition engine. The model has also been used to compare the prediction performance and emission data when operating the engine with methanol, ethanol and gasoline fuels. A series of an experimental tests were carried out on a single cylinder spark ignition engine to confirm the theoretical results of the mathematical model. Comparison of results indicates that alcohol seems to be a viable alternative fuel to gasoline with respect to efficient, operational and emission considerations.

Butanol could reduce emissions and alleviate the energy crisis as a bio-fuel used on engines, but the production cost problem limits the application of butanol. During the butanol production, ABE (Acetone-Butanol-Ethanol) is a critical intermediate product. Many studies researched the direct application of ABE on engines instead of butanol to solve the production cost problem of butanol. ABE has the defects of large ignition energy and vaporization heat. Hydrogen is a gaseous fuel with small ignition energy and high flame temperature. In this research, ABE port injection combines with hydrogen direct injection, forming a stratified state of the hydrogen-rich mixture around the spark plug. The engine speed is 1500 rpm, and λ is 1. Five αH2 (hydrogen blending fractions: 0, 5%, 10%, 15%, 20%) and five spark timings (5°, 10°, 15°, 20°, 25° CA BTDC) are studied to observe the effects of them on combustion and emissions of the test engine. The results show that hydrogen addition increases the maximum cylinder pressure and maximum heat release rate, increases the maximum cylinder temperature and IMEP, but the exhaust temperature decreases. The flame development period and flame propagation period shorten after adding hydrogen. Hydrogen addition improves HC and CO emissions but increases NOx emissions. Particle emissions decrease distinctly after hydrogen addition. Hydrogen changes the combustion properties of ABE and improves the test engine's power and emissions. The combustion in the cylinder becomes better with the increase of αH2, but a further increase in αH2 beyond 5% brings minor improvements on combustion.

This work demonstrated the first-ever cold-start operation of an ammonia (NH3)-fueled four-cylinder spark ignition engine with an on-board fuel reformer, applying autothermal reforming. In this system, an electrically heated NH3-air mixture was provided to a reforming catalyst and approximately 3 s was found to elapse between the start of engine rotation and the onset of combustion. Stable fast idle operation in conjunction with a cold start was realized with a H2-to-NH3 molar ratio of 2:1. Nearly zero NH3 emissions were achieved during cold start and fast idle until the engine warmed up, by adsorbing unburned NH3 passing through a three-way catalyst before the catalyst was sufficiently warmed up. The NH3 adsorption capacity of this system could be regenerated during the engine warm-up when the engine was running under lean conditions.

In this contribution, the investigation conducted on alternative fuels includes methanol 20% blended with gasoline 80% and emulsion-based fuel with the composition of gasoline 80%, ethanol 15%, and H2O 5% are compared with 100% conventional gasoline fuel. These fueled single-cylinders spark ignition engine is studied for checking their performance and emission characteristics as per future emission norms. This work is performed on One-dimensional AVL Boost Simulation Software. The simulations predicted the performance and emission characteristics were far lesser than conventional 100% gasoline. These fuels meet the strict emission regulations of Euro VII. The main purpose of this investigation is to use alternative fuels to improve the performance and emission characteristics of the single- cylinder spark ignition engine and reduce the consumption of fossil fuel reserves. This investigation led to the conclusion that by using methanol 20% in 80% gasoline and micro-emulsion, fuel improves the power, BSFC (brake specific fuel consumption), thermal efficiency and combustion properties of the single-cylinder spark-ignition engine. The CO, HC and NOx emissions were also reduced for alternative fuel than 100% gasoline fuel. The novel water-based emulsion fuel showed the lowest value of NOx emissions as compared to blended 20% methanol with 80% gasoline and 100% gasoline fuel.

From the beginning of IC engine era, it is trying to improve the performance and efficiency of internal combustion engine. In this study, numerically analysis on combustion of Propane, Propanol and Octane in SI engine have been done thoroughly and presented to assess the potentiality and highlighted the comparison. For this analysis thermodynamic engine cycle model is developed for numerical analysis. Mathematical models considering fundamental equation and empirical relation are implemented in a single cylinder 4 stroke spark ignition engine (system) with the help of FORTRAN 95 to find out heat losses, friction losses, output parameter etc. Single cylinder four-stroke spark-ignition (SI) engine is considered as system. In this study, different working parameters like 8 and 12 compression ratios with three different rpm 2000, 4000 & 6000 are considered for simulation. This study shows the different comparisons of energy-exergy content (%), as example of exhaust gas 35.08 & 17.82, 37.02 & 19.22, 37.79 & 19.79 for Octane (at compression ratio 8 and 2000, 4000, 6000 rpm) etc., which explains the potentiality content and the potentiality losses in different process like combustion, mixing of gases etc. It also shows for the fuel propane and propanol in similar way with changing different operating conditions. Maximum inside cylinder temperature, 1st law and 2nd law efficiencies were determined for the fuels with respect to different compression ratio and engine speed.

The object of this work was to learn more about the effect of fuel-air mixture upon the performance of spark ignition engines, and to determine how variations in mixture velocity after leaving engine carburetor alter the combustion process. To provide effective means for producing and measuring the mixture velocity, all tests were made in a multi-cylinder spark ignition engine using a blade swiler. The effect of mixture motion on the volumetric efficiency, rate of pressure rise , brake thermal efficiency, and mixturedistribution were determined for wide range of engine speeds and loads. The results reveal that a mixture motion improve the mixture quality and quantity of the engine cylinders, this effect gives evenly gas pressure cycles. The engine Diane thermal efficiency depend upon tue type of swirler motion.

In this research, the impacts of the use of a new fuel additive called octamix, which is obtained by mixing trioctyl borate as a boron source, ammonia borane as a hydrogen enhancer and ethyl alcohol, on the performance and emission values in a gasoline engine have been investigated experimentally. The experiments were carried out using four different fuel mixtures obtained by mixing octamix with gasoline at 0.5%, 1%, 2% and 3% by volume and pure gasoline at different engine load values in a single cylinder spark ignition engine. While brake thermal efficiency and brake specific fuel consumption were evaluated as performance parameters, carbon monoxide, hydrocarbon, carbon dioxide and nitrogen oxide were taken into consideration as emission responses. Experimental results revealed that using octamix higher than 0.5% was not efficient in terms of performance and emission. With the use of a fuel blend containing 0.5% octamix, overall emission and performance values improved but deteriorated with other octamix-containing fuels. According to the results, it can be said that octamix fuel is more suitable for use as a fuel additive rather than as a stand-alone fuel for gasoline engines and the use of only 0.5% octamix-containing fuel mixture is efficient.

Lean combustion has the potential to achieve higher thermal efficiency for internal combustion (IC) engines. However, natural gas engines often suffer from slow burning rate and large cyclic variations when adopting lean combustion. In this study, using a dual-fuel optical engine with a high compression ratio, the effects of direct-injected hydrogen on lean combustion characteristics of natural gas engines was investigated, emphasizing the role of hydrogen injection timing. Synchronization measurement of in-cylinder pressure and high-speed photography was performed for combustion analysis. The results show that the direct-injected hydrogen exhibits great improvement in lean combustion instability and power capability of natural gas engines. Visual images and combustion phasing analysis indicate that the underlying reasons are ascribed to the fast flame propagation with hydrogen addition. Regarding the direct injection timings, it is found that late injection of direct-injected hydrogen can achieve higher thermal efficiency, manifesting advanced combustion phasing, and increased heat release rate. Specifically, the flame propagation speed is elevated by approximately 50% at −100 CAD than that of −250 CAD. Further analysis indicates that the improvement of engine performance is ascribed to the increased volumetric efficiency and in-cylinder turbulence intensity, manifesting distinct flame centroid pathways at different injection timings. The current study provides insights into the combustion optimization of natural gas engines under lean burning conditions.

Experimental and theoretical investigations were made a torch chamber spark ignition engine to determine the effect of some design and operational parameters on engine emissions. The experimental study was performed using a modified Deutz-Diesel engine developed to be a torch chamber spark ignition engine. During this investigation, two main design parameters were investigated namely, the connecting passage shape and the flame initiation point. In this work three ignition point location and two different connecting passage shapes were investigated over a wide range of mixture strength, engine speed and throttle opening. A mathematical model of compression, combustion and expansion processes of the torch chamber spark ignition engine has also been developed. This model aims at estimating the effect of mixture strength on the NO and CO rates of formation in this engine. In developing the model, experimental data obtained on the same engine are used. The experimental results reveal that, the configuration of the connecting passage has a great effect on emissions from the torch chamber S.I.E. It also reveals that, as the spark plug is extended inside the combustion chamber, engine emissions decrease. The optimum case is reached when using a convergent divergent passage coupled with the extended spark plug. The trends obtained from the mathematical simulation are in a good agreement with the experimental one.

Thermal processing (torrefaction, pyrolysis, and gasification), as a technology can provide environmentally friendly use of plastic waste. However, it faces a problem with respect to its by-products. Pyrolysis oil obtained using this technology is seen as a substance that is extremely harmful for living creatures and that needs to be neutralized. Due to its relatively high calorific value, it can be considered as a potential fuel for internal combustion spark-ignition engines. In order make the combustion process effective, pyrolysis oil is blended with ethanol, which is commonly used as a fuel for flexible fuel cars. This article presents results from combustion tests conducted on a single-cylinder research engine at full load working at 600 rpm at a compression ratio of 9.5:1, and an equivalence ratio of 1. The analysis showed improvements in combustion and engine performance. It was found that, due to the higher calorific value of the blend, the engine possessed a higher indicated mean effective pressure. It was also found that optimal spark timing for this ethanol-pyrolysis oil blend was improved at a crank angle of 2–3° at 600 rpm. In summary, ethanol-pyrolysis oil blends at a volumetric ratio of 3:1 (25% pyrolysis oil) can successfully substitute ethanol in spark-ignition engines, particularly for vehicles with flexible fuel type.

The cyclic variability in a spark-ignition (SI) engine is examined fueled with methane/hydrogen blends with the use of an in-house computational fluid dynamics (CFD) code. A recent methodology is followed, which has been developed with the main aim at providing accurate predictions of the coefficient of variation (COV) of the indicated mean effective pressure (IMEP) in a fraction of time. Instead of simulating several tens of engine cycles, the methodology is based on the numerical results obtained from just 5 cycles, which are then processed for developing suitable fitted correlations of the main parameters as a function of a normalized distance. The latter expresses the distance of the spheres of the initial flame within the computational cell at the spark-plug region with the local turbulent eddy, and provides a smooth transition from the laminar burning regime to the fully turbulent one. This sub-model is included in the ignition numerical approach and is applied here in a SI engine with 3 different hydrogen contents, 10%, 30% and 50%, and three equivalence ratios, 1, 0.8 and 0.7, showing that the COV of IMEP is well predicted compared to the available measured data. Other parameters of engine cycle variations are also examined, such as the distribution of the IMEP. The variability of NO (nitric oxide) emissions is also examined, showing that for the stoichiometric cases it follows a distribution similar to a normal (Gaussian) one, while for lower ratios it is positively skewed. Overall, the methodology seems to provide reliable results for the whole range of the operating conditions examined, while the next steps of this activity will focus on similar cases for engine with variable speed and load, with the final goal to include additional mechanisms that contribute to the engine cycle variations.

The article presented is concerned with studying the effect of ethanol, and iso-butanol concentrations in a spark ignited, single-cylinder four-stroke engine on the engine parameters such as performance, combustion, and emission. The engine performance characteristics such as specific fuel consumption, brake thermal efficiency, and in-cylinder pressure were examined for different engine's operational loads. Similarly, the emission parameters such as CO, HC, and NOx were analyzed. Results showed that the influence of iso-butanol and ethanol improved the thermal by 6% than that of petrol. As a result of adding iso-butanol and ethanol with petrol, fuel consumption reduction can be observed. The CO, NOx, and HC emission were noted as 1.25% by vol, 146 ppm, and 175 ppm, respectively, whereas the CO2 is noted as 7.7% for 5% ethanol and 15% Iso-butanol. The optimum concentration of iso-butanol and ethanol was found as 15 and 5%, respectively, which improved the engine operating parameters and decreased the emission produced. The emission such as CO, Nox, and HC shows a significant reduction; on the other hand, the CO2 showed a drastic rise for the optimized blend proving the progression of complete combustion

To better understand the formation and evolution processes of soot, the two-color laser induced incandescence diagnostic method was applied on a single cylinder optical direct injection spark ignition engine. Soot volume fraction was measured, and soot distribution was imaged as cyclic fuel quantity changes. The results show that 45.5 mg/cycle generates the most soot at the same measure plane. Pool fire dominates the formation of soot in the tested engine and generates more soot on the top surface of the piston near the injector. In-cylinder soot increases until 42°CA ATDC and then reduces due to oxidation. Pool fire continues through the expansion stroke till 52°CA ATDC, and then soot cloud gathers near the 10 mm plane. After 82°CA ATDC, in-cylinder soot basically in equilibrium, and residual soot moves follow the in-cylinder flow randomly and evenly distributes within the whole combustion chamber. With increasing cyclic fuel quantity, particles number concentration gradually increases and their distribution present dual-peak shape. In detail, 45.5 mg/cycle emits the most accumulation mode particles while 52 mg/cycle emits the most nucleation mode particles.

The only product of hydrogen combustion is water, so it is very clean. In this paper, the effects of low hydrogen content and FKR on the performance of the GDI engine are mainly studied. The simulation results show that adding less than 3% hydrogen in the GDI engine can improve the BP and BT of the engine under typical urban conditions such as 1500 rpm and 2000 rpm. As the hydrogen volume fraction and the FKR increase, the LFS of the mixture increases, resulting in a shorter ignition delay, combustion delay, and 10–90 % MFB. However, an increase in FKR results in a decrease in the BP and BT. In terms of fuel economy, the BSFC decreases as the hydrogen content increases, but as FKR increases, the BSFC increases. In terms of emissions, the proportion of hydrogen increases, HC and NOx emissions increase, and CO and CO2 emissions decrease. Therefore, adding hydrogen to the GDI engine while adjusting the FKR can improve the dynamic performance of the engine and reduce CO and CO2 exhaust emissions.

Renewable energy called normal -butanol is a possible alternative fuel for automobile vehicles like some other possible fuel such as compressed natural gas ( CNG ) , liquid petroleum gas ( LPG ) , ethanol, and methanol. Bio-butanol or normal -butanol is also a meritable energy source to substitute for regular fossil fuels. The normal -butanol has recently started to use as a possible substitute fuel to regular fuels for internal combustion engines to attain eco-friendly and capital benefits. As compared to regular energy sources in internal combustion engines, normal -butanol has some benefits, so it shows the potential to decrease tailpipe emission and an increase in positive network delivery. The current work carried out to investigate the performance and emission characteristics of dual spark plug ignition engine fuelled with normal -butanol as additive fuel by adopting 10:1 and 10.5:1 compression ratio s . The experimental results reveal that when compared between 10:1 and 10.5:1 compression ratio s , brake power ( BP ) is increased by 3.5 % and 3.2 % for normal- B utanol 35 (nB35) blend and energy efficiency increased by 2.72 % and 2.14 % for nB35 blend at a part and full load for 10.5:1 compression ratio . The n-butanol create a greater impact on tailpipe emissions that the carbon monoxide ( CO ) decreased by 32 %, 29 %, and hydrocarbon ( HC ) reduced by 2.38 % and 2.22 % for nB35 blend at a part and full load condition respectively. The experimental results on dual spark ignition engine using n-butanol as additive fuel by varying compression ratio reveals that n-butanol can be a suitable replacement energy source for the automobile sector in the nearest future.

Hydrogen energy has received much attention in recent years due to its reliability and non-carbon products. However, it has been found that the backfire phenomenon plays a major part in limiting power and torque in the hydrogen internal combustion engine (H2ICE). Much research in recent years has considered turbocharger as a useful method to improve the power of H2ICE. Although the result of boosting a system with turbocharger became enhanced when compared to the natural aspiration system. Unfortunately, there were unsolved problems in exhaust backpressure and pumping losses that hindering the practical utilisation of H2ICE. This paper investigated the experiment of 2.4 L supercharged port fuel injection engine at 2000 rpm. Air excess ratio (lambda) was varied from stoichiometric to 2.8 by adjusting the boosting amount in supercharger, and throttling of the air. The hydrogen injection amount were maintained the same with turbocharger condition; spark advance timing was set at maximum brake torque. It was observed that by boosting engine with supercharger, the lower pumping loss and higher indicated mean pressure had been obtained when compared to turbocharger boosted engine under low-load condition. However, some additional power required for supercharging that lowers output of the engine.

It is generally accepted that knock in spark-ignition engines is caused by end-gas autoignition. However, limited studies regarding to the effect of the inhomogeneity of temperature and composition...

In this contribution two Alternative fuels in fixed proportions were compared with conventional 100% gasoline fuel on a constant Speed single cylinder based generator. This work defines the complete state of the art work done on computational Simulation Software on AVL Boost. In this work, we have compared the performance and emission characteristics of single cylinder spark Ignition engine constant speed of 3000 rpm fuelled conventional Gasoline 100% with blended Alternative fuel Ethanol15% with 85% Gasoline, and water-Ethanol based micro-emulsion fuel Gasoline 85% Ethanol 10% and H2O 5% on licence based Simulation Software AVL Boost. The performance parameters were checked for all the three types of fuels and emission characteristics were compared with all the three types of fuels. The results were very promising for water-Ethanol based micro-emulsion fuel as far as the emission characteristics are concerned. Ethanol 15% blends with 85% Gasoline also showed very less emissions as compared to conventional 100% Gasoline. The power & Torque has shown slightly more increase for conventional 100% Gasoline fuel as compared to other two Alternative Fuels. However, emissions were far lesser for water-Ethanol based micro-emulsion and Ethanol blended fuel. The main aim of this investigation is to reduce the emissions and trying to meet the future emission standards Euro 7.

Residual gas fraction and combustion phase are two important variables in spark ignition engines since affect thermal efficiency, emissions and combustion stability. In-cylinder pressure sensors are the most extended signal used as feedback for closed-loop spark advance and residual gas fraction control. However, pressure sensors are still affected by challenges such as durability and cost. This work presents a model-based residual gas fraction control with spark advance optimization. The controller is validated in a light-duty spark ignition engine, being able to control the residuals both in steady and transient conditions, showing the potential to replace in-cylinder pressure sensors.

The Experiment was conducted on single cylinder two – stroke spark-ignition engine. Make it lesser time in chemical delay in combustion process the catalyst material such as brass was coated on piston crown with 300 µm thickness. The coated piston was tested with pure gasoline and gasoline-methanol blends and compared performance and emission characteristics between conventional piston and brass coated piston in trail- I. With pure gasoline coated piston given better results than a conventional piston engine. The improvement of results the test was conducted with methanol blends in the % volume 10%, 20%, and 30% named as M10, M20, and M30 in the trail-II. Out of three different blends with M20 (20% of methanol and 80% of gasoline) given a better reduction in exhaust emissions like hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO2) and NOx. Pure gasoline with brass coated piston enhanced performance results such as brake thermal efficiency, specific fuel consumption, and mechanical efficiencies upon conventional two stroke spark-ignition engine. Observing trail -II results with blends on coated piston 20% volume (M20) given optimum values more than that it is noticed poor performance and emissions characteristics on brass coated piston.

This paper has illustrated a "near wall" combustion model for a spark ignition engine that was included in a two-zone thermodynamic model. The model has calculated cylinder pressure and temperature, composition, as well as heat transfer of fresh and combustion gas. The CO submodel used a simplified chemical equation to calculate the dynamics of CO during the expansion phase. Subsequently, the HC submodel is introduced, and the post-flame oxidation of un-burned hydrocarbon was affected by the reaction/diffusion phenomenon. After burning 90% of the fuel, the hydrocarbon reaction dominates at a very late stage of combustion. This modeling method can more directly describe the ?near wall? flame reaction and its contribution to the total heat release rate.

Engine knock is a critical phenomenon engine designers strive to minimize in the world today. Before now, this has made tetra ethyl lead (TEL) an option for minimizing knock. The basic essence of tetra ethyl lead is to enhance octane rating of petrol which is a vital factor to knocking ability. However, the health and environmental challenges associated with the use of tetra ethyl lead propel the desire to replace it with a better environmental and health friendly substance that will at the same time boost octane rating and give a smoother engine operation. Hence, ethanol was considered in this work at a constant speed test of 2000 rpm and compared to leaded petrol as baseline petrol. BSFC of 0.703 kg\kWhr was obtained with 20/80 compared to 0.709 kg\kWhr obtained with 0/100 as baseline fuel. Maximum brake power of 0.74 kW occurred at a bmep of 1.235 bar with 15/85 ethanol/petrol. Similarly, maximum brake thermal efficiency of 13.44% was obtained with 20/80 ethanol/petrol compared to 11.49% obtained with leaded petrol as baseline petrol. It is indicated that maximum power output, low BSFC and low petrol consumption was obtained with 20/80 ethanol/petrol blend. It is convincible that 20/80 blend ratio offer good alternative to other antiknock agents which are associated with harmful consequences to man and environment. The implication of this work is that a definite blend for optimum performance and more environmentally friendly antiknock agent is established.

As one of the most common engine types in nowadays, the thermal efficiency of spark-Ignition (SI) engine is limited due to the lower compression ratio. Various technical solutions have been proposed to suppress knock and improve compression ratio of SI engines. In this paper, an new technical solution based on electromagnetic valve train (EMVT) was proposed to suppress knock of spark ignition engines, so that high compression ratio (HCR) engine (13:5) was obtained. Moreover, experimental and numerical analyses were carried out to optimize the proposed EMVT strategy. The result showed that the proposed EMVT strategies could well suppress the engine knock by reducing end-gas temperature and pressure and improving the spark-flame rate, resulting in significantly enhanced power, economic, and emission characteristics of SI engines. This study provides theoretical basis and technical approach for the development of internal combustion engines with high efficiency and high compression ratio.

Acetone-Butanol-Ethanol (ABE) is an essential product in the production process of butanol, which is considered as an effective way to replace butanol used in engines because of the lower production cost of ABE. Hydrogen is an ideal fuel for engines because of its low ignition energy and high flame propagation speed. In this study, the effects of hydrogen addition on the combustion and emission characteristics of a spark ignition ABE engine under lean-burn conditions are investigated. Specifically, five hydrogen blending ratios (0, 5%, 10%, 15%, 20%) and three λ values (1, 1.1, 1.2) are studied. The results show that adding hydrogen can increase the maximum cylinder temperature and pressure, decrease the flame development and propagation duration of the hydrogen/ABE dual-fuel SI engine. In addition, hydrogen addition can reduce the COVIMEP, BSFC, CO, HC emissions, and improve the IMEP, but increase NOx emissions; however, a lower NOx emissions for the hydrogen/ABE engine working under learn-burn conditions (λ equals 1.2) can be achieved with a suitable proportion of hydrogen adding (proportion = 5%) than that of engine working under stoichiometric air-fuel ratio condition. Thus, hydrogen addition can facilitate the combustion of ABE in engines, especially under lean-burn conditions.

This study investigates the cyclic dynamics of cumulative heat release data past the edge of stability in a dilute spark-ignition engine. Emphasis is placed on analyzing the cyclic dynamics near the dilute limit where partial burns and misfires are frequent. These events are often followed by a higher-energy cycle due to the feed-forward mechanism present in the residual gases. These patterns are deterministic and increase the coefficient of variation to undesirable levels. Symbol sequence analysis was used to investigate the cyclic dynamics of these low–high patterns. The heat release was partitioned on an energy basis to give physical meaning to each partition and each sequence created when analyzing the symbol sequence results. This partitioning method provided insight into the differences in the dynamics when operating in the misfire or partial burn regime. These differences could impact the control method used.

LPG is an alternative fuel that commonly used in spark ignition engine. The research on introducing the LPG into the combustion chamber has been extended to the liquid injection rather than conventional method which is gas injection. The objective of this study specifically is to evaluate the effects of liquid LPG injection on the combustion stability as compared to the gasoline fuel. The study was conducted using 1600cc naturally aspirated engine at 2000rpm and 3000rpm at various throttle position, which were 25%, 50%, 75% and 100% of its opening. The statistical analysis has been used in determining the combustion effectiveness through peak pressure analysis from 250 continuous combustion cycle. The results were compared with the gasoline fuel for each experimental condition. The results showed that liquid LPG injection has produced better combustion stability than gasoline fuel at almost all tested conditions.

In this study, the performance of different spark plugs was tested with varied spark gap sizes in a spark-ignited engine. Gasoline fuel was enriched with hydrogen and methanol to evaluate how much they affect the performance of the engine. The engine tests were performed with a four-stroke, single-cylinder, naturally aspirated, variable compression ratio (VCR) spark ignition engine. 1500 rpm engine speed and MBT for spark timing were applied throughout all experiments. Iridium, platinum and conventional (copper) spark plugs were tested using 3 different spark plug gaps (SPG) (0.6 mm, 0.8 mm, 1 mm). Depending on the experimental condition, hydrogen was added with 3 l/min of flow rate and methanol was used with 10% of volume fraction in the total liquid fuel. As for performance criteria, brake power (BP) and brake specific fuel consumption (BSFC) values were obtained from the test engine. According to the findings, platinum and iridium spark plugs had shown better performance than conventional spark plugs. The increment of SPG size improved the performance of the engine, too. On the other hand, despite methanol addition to gasoline fuel reduced performance, this loss could be compensated by hydrogen enrichment. Additionally, multiple linear regression (MLR) technique was applied through experimental results to obtain a linear relationship between explanatory variables (inputs) and response variables (outputs). An MLR model was set with four selected input variables (spark plug type, hydrogen flow rate, methanol ratio, and spark gap) to estimate BP and BSFC. Prediction equations showed that experimentally obtained results were in good agreement with MLR results.

This work presents the concept of ternary blends of gasoline, ethanol and methanol (GEM) in which stoichiometric air to fuel ratio is controlled to 13.2, same as that of conventional binary E30 (Gasoline 70% + Ethanol 30% (v/v)) fuel blend. The formulated E30 equivalent ternary blends have approximately the same energy density, lower heating value and octane number as target binary E30 blend such that they can be a drop-in alternative to it. The experimental work was performed to investigate the performance, emission and combustion characteristics of PFI SI engine using E30 equivalent GEM blends. The engine tests were conducted at constant load while varying the engine speed from 1700 to 3300 rpm by varying the throttle position. The performance, emission and combustion results were measured and compared with pure gasoline. The results show that formulated GEM blends have similar brake thermal efficiency, in-cylinder pressure and net heat release as binary E30 blend and are improved when compared to pure gasoline. It is also noted that exhaust emissions such as Carbon monoxide (CO), unburned hydrocarbons (HC) show decreased values and increase in Nitrogen Oxide (NOx) for blended fuels compared to pure gasoline due to oxygenated nature of alcohol fuels.

By evaluating combustion duration and flame development, it is possible to evaluate the effects of utilizing a new type of fuel. This allows for optimization of the operational parameters such as the ignition timing, air–fuel ratio, and throttle opening with respect to efficiency, knock, emissions, and performance. In this work, the combustion of a Brazilian hydrous ethanol fuel was evaluated in a commercial flexfuel engine. Investigations were conducted by performing a heat release analysis of the experimental data and providing combustion characteristics. The experimental design comprised of variations in engine speed, load, ignition timing, and air–fuel ratio under lean condition. The results indicated the relationship between the engine parameters and combustion characteristics under a wide range of operational conditions, and identified the relationship between the physical characteristics of the fuels and their combustion in the commercial engine. For high engine speed, lean combustion presented a similar duration to the stoichiometric combustion duration. When comparing the combustion characteristics obtained for the hydrous ethanol with gasoline combustion, the main differences noted were reduced sensitivity to detonation and a shorter duration of combustion, although the temperature at the start of combustion was lower for ethanol. In addition to shorter combustion duration, ethanol presented a lower value for the Wiebe exponent. The results obtained from the combustion duration values and Wiebe function parameters enable the composition of a set of data required for a simplified combustion simulation.

The type of fuel, engine speed, and load are some of the parameters, which influence engine noise, vibrations, and exhaust emissions of an internal combustion engine. The present investigation is c...

One of the most effective solutions for improving the performance and reducing the emission of spark-ignition engines isintroducing a hybrid fuel with gasoline. Hydroxy gas (HHO) that is generated from the water electrolyzes process has a significant effect in enhancing the thermal efficiency and reducing fuel consumption rate and the resulted combustion emissions of SI engine. Because HHO gas has significant advantages rather than fossil fuels. In this study, a fuel dry cell is constructed and tested in different concentrations of electrolysis water solutions and with alternating the number of neutral plates, to obtain the most economic, safe, and suitable cell for the desired engine operation conditions. The engine used is a 183 CC single-cylinder air-cooled (Robin EY 20-3) without any change in engine construction. The load used for this purpose is a centrifugal water pump with a maximum delivery flow rate of 520 L/min. First, the engine is allowed to run separately without the cell under different speeds of 1200, 1500,2000,2500,3000 and 3500 rpm, then the cell isconnected to the engine. Many different operating parameters are measured such as pump flow rate, fuel consumption rate, water pressure, exhaust temperature, and engine emissions; HC and CO. The experimental results show that increasing the concentration of electrolysis solution or reducing the number of neutral plates increased the production rate of the gas, but it has an undesirable effect on increasing the temperature of the cell. And for engine performance, the average enhancement of engine efficiency, reductions in brake specific fuel consumption, reduction in CO and HC emissions are 5.44%, 16.9%, 4.8%, and 5.5%, respectively

Hydroxy gas (HHO) is one of the potential alternative fuels for spark ignition (SI) engine, notably due to simultaneous increase in engine performance and reduction in exhaust emissions. However, impact of HHO gas on lubrication oil for longer periods of engine operation has not yet been studied. Current study focuses on investigation of the effect of gasoline, CNG and CNG-HHO blend on lubrication oil deterioration along with engine performance and emissions in SI engine. HHO unit produces HHO gas at 4.72 L/min by using 6 g/L of KOH in the aqueous solution. CNG was supplied to the test engine at a pressure of 0.11 MPa using an electronically controlled solenoid valve. Engine tests were carried out at different speeds at 80% open throttle condition and various performance parameters such as brake power (BP), brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature and exhaust emissions (HC, CO2, CO and NOx) were investigated. In addition, various lubrication oil samples were extracted over 120 h of engine running while topping for drain out volume and samples were analyzed as per ASTM standards. CNG-HHO blend exhibited better performance i.e. 15.4% increase in average BP in comparison to CNG, however, 15.1% decrease was observed when compared to gasoline. CNG-HHO outperformed gasoline and CNG in the case of HC, CO2, CO and brake specific fuel consumption (31.1% decrease in comparison to gasoline). On the other hand, CNG-HHO produced higher average NOx (12.9%) when compared to CNG only. Furthermore, lubrication oil condition (kinematic viscosity, water contents, flash point and total base number (TBN)), wear debris (Iron (Fe), Aluminum (Al), Copper (Cu), Chromium (Cr)) and additives depletion (Zinc (Zn), Calcium (Ca)) presented a significant degradation in the case of CNG-HHO blend as compared to gasoline and CNG. Lubrication oil analyses illustrated 19.6%, 12.8% and 14.2% decrease in average viscosity, flash point and TBN for CNG-HHO blend respectively. However, average water contents, Fe, Al and Cu mass concentration appeared 2.7%, 25×10−6, 19×10−6, and 22×10−6 in lubrication oil for CNG-HHO respectively.