Single Cylinder Spark Ignition Engine Research Articles

Effects of variable valve timing on the air flow parameters in an electromechanical valve mechanism – A cfd study

In this study, volumetric efficiency, air flow rates, and cylinder pressure values were experimentally determined for a single-cylinder spark-ignition engine having conventional camshafts. Cold flow analysis was carried out using the computational fluid dynamics (CFD) method with importing combustion chamber and flow volumes of the suction and exhaust ports of the engine. After validating analyzes results with experimental data for different revolutions (RPMs), analyses were repeated using electromechanical valve mechanism (EMV) cam profiles. In the case of using EMV, advancing the intake valve opening time and advancing and retarding exhaust valve closing were simulated with CFD software. Simulations where different cam profiles were used for each revolution, volumetric efficiency, in-cylinder pressure, swirl and tumble ratio, in-cylinder total mass, and air flow rates in the cylinder were investigated numerically. As a result of the obtained data, it was seen that the use of EMV at low RPMs caused a decrease in the volumetric efficiency according to the conventional camshaft valve lifting amount and timing and it caused an increase in the volumetric efficiency at high RPMs. According to the results, it was understood that the effect of intake valve closing time is important on volumetric efficiency. Additionally, this study shows that the swirl ratio is significantly affected by EMV system.

Experimental Investigation of the Hydroxy Gas Generation as a Clean Energy Source for Spark Ignition Engine Operation Using Different Electrolytes

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.

Experimental study of mechanical losses of single-cylinder spark-ignited engine

Experimental study of mechanical losses of single-cylinder spark-ignited engine

Theoretical and Experimental Studies on The Combustion of Synthetic Fuels in Spark Ignition Engines.(Dept.M)

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.

Influence of Swirl Flow on Combustion and Emissions in Spark-Ignition Experimental Engine

AbstractThis paper presents a numerical study of swirl flow effects on the combustion and emissions in single-cylinder spark ignition engine. First, a three-dimensional (3D) computational fluid dyn...

Computational optimization of CH4/H2/CO blends in a spark-ignition engine using quasi-dimensional combustion model

Recent research has proven that computational fluid dynamics (CFD) modeling in combination with a genetic algorithm (GA) algorithm is an effective methodology to optimize the design of internal combustion (IC) engines. However, this approach is time consuming, which limits the practical application of it. This study addresses this issue by using a quasi-dimensional (QD) model in combination with a GA to find optimal fuel composition in a spark ignition (SI) engine operated with CH4/H2/CO fuel blends. The QD model for the simulation of combustion of the fuel blends coupled with a chemical kinetics tool for ignition chemistry was validated with respect to measured pressure traces and NOx emissions of a small size single-cylinder SI engine operated with CH4/H2 blends. Calibration was carried out to assess the predictive capability of the QD model, and the effect of hydrogen addition on the lean limit extension of the methane fueled engine was studied. A GA approach was then used to optimize the blend composition and engine input parameters based on a fitness function. The QD-GA methodology was implemented to simultaneously investigate the effects of three input parameters, i.e., fuel composition, air–fuel equivalence ratio and spark timing on NOxemissions and indicated thermal efficiency (ITE) for the engine. The results found indicated that this approach could provide optimal fuel blends and operating conditions with considerable lower NOx emissions together with improved thermal efficiencies compared to the methane fueled engine. The presented computationally-efficient methodology can also be used for other fuel blends and engine configurations.

The Effect of Injection Parameters on Fuel Consumption and Emissions in A PFI Small Spark Ignition Engine

Mixture formation in port fuel spark ignition engines is one of the most im-portant parameters, which affect combustion and emissions. In this study, the ef-fects of different injection start timings and some other port fuel injection (PFI) parameters on the performance and emissions of a water cooled and single cylin-der spark ignition engine were examined experimentally. The experiments were performed at different engine speeds (1200 and 1500 rpm for effect of injection pressure and 1500 rpm for changing injection timings) and different engine loads (3 bar and 5 bar for injection pressure and 1 bar and 5 bar for start of injection). The start of injection was chosen according to intake pressure measurements. The experiment results showed that brake specific fuel consumption (BSFC) and total hydrocarbon (THC) emissions are increased by the increase of the injection pressure. Because with the increase of injection pressure, the fuel can reach the intake manifold wall or intake valve. Therefore, the fuel enters the cylinder as a droplet. Different start of injection experiments showed that injection times have an effect on emissions and performance. The minimum brake specific fuel con-sumption and THC values were obtained at -243 °CA value of injection start. The twice injection in one cycle increased brake specific fuel consumption and THC emissions.

Parametric Investigation on Single Cylinder Spark Ignition Engine Fueled Methanol Blends; Water-Based Micro Emulsions and Conventional Gasoline

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.

Comparative assessment of stoichiometric and lean combustion modes in boosted spark-ignition engine fueled with syngas

Synthesis gas (syngas) is considered an intermediate step between conventional carbon-based fuels and future hydrogen-based fuels. Spark-ignition (SI) engines are suitable for converting the chemical energy of syngas for small-scale electrical power generation. However, syngas-fueled SI engines have lower power outputs and thermal efficiencies than SI engines fueled with conventional fuels such as gasoline and natural gas do. The objective of this study was to compare the stoichiometric and lean combustion modes in a single-cylinder SI engine to determine the optimal combustion mode for the development of a syngas engine generator with high power and high efficiency. A high gross indicate power was achieved in the stoichiometric combustion mode by increasing the intake pressure, owing to the increase in the volumetric efficiency and syngas fuel input. The gross indicated thermal efficiency (ITE) improved as the compression ratio was increased from 10:1 to 17.1:1, owing to the high peak heat release rate and short combustion duration. In the lean combustion mode, high gross ITEs were achieved by increasing the excess air ratio to 2.5, but the additional increase led to low combustion efficiencies. However, the gross indicated power decreased with an increase in the excess air ratio. The low gross indicated power was increased through intake boosting. Based on a parametric study, the optimal compression ratio for the stoichiometric combustion mode was selected to be 15:1. Pre-ignition occurred in the stoichiometric combustion mode at a compression ratio of 17.1:1 and an intake pressure of 0.16 MPa. Engine operation with a high compression ratio of 17.1:1 was possible in the lean combustion mode owing to the low combustion temperature. The gross ITE in the lean combustion mode was 18.4% higher than that in the stoichiometric combustion mode, mainly because of a significant reduction in the heat transfer loss. However, the gross indicated power in the lean combustion mode was 25.6% lower than that in the stoichiometric combustion mode.

Influence of plasma-assisted ignition on flame propagation and performance in a spark-ignition engine

Lean-burn is an attractive concept for reasons of high thermal efficiency and low nitrogen oxide (NOx) emissions, however, successful implementation in spark-ignition (SI) engines turned out to be challenging because of misfire or partial burn caused by attenuated flame propagation. In order to overcome this issue, microwave-assisted plasma ignition system (MAPIS) has been applied in combustion systems. The MAPIS consists of a conventional ignition coil, a non-resistor spark plug, a mixing unit, a waveguide, and a magnetron (2.45GHz, 3kW). A series of experiments was carried out to understand discharge characteristics and to validate its performance in a constant volume vessel as well as in a single-cylinder spark-ignition engine. The fundamental investigation based on optical emission spectroscopy and flame imaging showed that the ejection of the microwave was beneficial to produce more reactive species such as OH and O radicals thanks to higher electron temperature than conventional spark ignition. The lean limit was able to be extended up to an equivalence ratio of 0.5 based on a larger initial flame kernel size with MAPIS in the vessel test. Meanwhile, in the engine test, combustion stability was noticeably improved showing smaller cycle-to-cycle fluctuations in in-cylinder pressure. Improvement in fuel efficiency up to 6% could be achieved by stable operation under fuel-lean conditions. In terms of emissions, MAPIS was advantageous to reduce carbon monoxide (CO) emissions by promoting more complete combustion.

Performance of direct injected propane and gasoline in a high stroke-to-bore ratio SI engine: Pathways to diesel efficiency parity with ultra low soot

This work explores pathways to achieve diesel-like, high-efficiency combustion with stoichiometric 3-way catalyst compatible combustion in a single-cylinder spark ignition (SI) research engine. A unique high stroke-to-bore engine design (1.5:1) with cooled exhaust gas recirculation (EGR) and high compression ratio ( rc) was used to improve engine efficiency by up to 30% compared with a production turbocharged gasoline direct injection spark ignition engine. Engine experiments were conducted with both 91 RON E10 gasoline and liquified petroleum gas (LPG) (i.e. autogas) and were compared to legacy gasoline data on the production engine. Geometric compression ratio ( rc) of 13.3:1 was used for both fuels with additional experiments at 16.8:1 for LPG only. Measurements of exhaust soot particle size and number concentrations were made with both fuels. Significant reduction in soot particles across the whole particle size range were achieved with LPG due to the elimination of in-cylinder liquid films. The effects of EGR, late intake valve closing (IVC) and fuel characteristics were investigated through their effects on efficiency, combustion stability and soot production. Results of 47% gross thermal efficiency, and 45% net thermal efficiency at stoichiometric engine operation, at up to 17 bar IMEP and 2000 r/min with 16.8:1 rc were achieved with LPG. Estimated brake efficiency values were compared to a contemporary medium duty diesel engine illustrating the benefits of the chosen path for achieving diesel efficiency parity.

Emission test on four-stroke single-cylinder S.IENGINE by optimised convergent-type intake manifold

ABSTRACT Nowadays, automobile has become a part of human life, especially two wheelers. In the recent era, the production of two wheelers has increased significantly which leads to an increase in emissions. In this research work, a single-cylinder spark ignition engine is chosen to improve its performance by analysing the intake manifold through the theory of convergent principle convergent. This work focuses on the design of an intake manifold with optimised convergent to the study of the air flow through designed intake manifold has been performed by using CFD analysis software. On comparison of the analysis results, an optimised intake manifold, which increases maximum air flow velocity inside the cylinder, has been selected for efficient combustion. Experimental Studies on emission level reduction show that the flow harnessing in intake manifold of IC engine can yield improvement in engine torque up to 10% along with a nominal decrease in emission level.

Performance and emission characteristics of a single cylinder spark ignition engine fuelled by ethanol-H2O based micro-emulsion, blended ethanol, and CNG as an alternative fuel

In this work, the 15% ethanol blended with gasoline 85% micro-emulsions, and CNG were computationally investigated on one-dimensional simulation software AVL Boost for predicting the emission and performance of the single cylinder spark ignition engine. The engine properties taken for the single cylinder spark ignition engine are the same engine that is present in the lab as the constant speed single cylinder based generator. The water based emulsion fuel, which is prepared in the lab taking its composition as gasoline 85%, ethanol 15%, and H2O 5%, and the same composition was used in the AVL Boost Software. Finally, CNG was also used to check its emissions and performance on the same software and then was compared with the micro-emulsion and ethanol blended gasoline. This study explains how the three types of fuel performed on the same engine and predicted its performance and emission formation comparatively.

Computational parametric investigation on single cylinder constant speed spark ignition engine fuelled water-based micro-emulsion, ethanol blends, and conventional gasoline

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.

Experimental Investigation of Performance and Emissions of Spark Ignition Engine Fueled with Blends of HHO Gas with Gasoline and CNG

Fossil fuels are widely used all over the world to power the motor vehicles. Due to superfluous consumption of these fuels, their reservoirs are depleting continuously. The huge demand of crude oil has caused the unprecedented price rise, environmental pollution, and global warming which directly affects the living beings as well as the surroundings in which they are surviving. Alternative fuels can suffice the demand with less adverse effects on the environment through the means of different sustainable technologies. Hydroxy gas (HHO) can be effective source of energy to combat these prominent issues. This work covers the experimental analysis of different parameters related to advantages and disadvantages of using HHO as a blend with gasoline and CNG fuel mixture. The analysis is based on engine performance and emissions. The experiments were performed on engine model fueled with a mixture of fuel and HHO gas. HHO was used as a fuel supplement. A compact HHO gas kit was installed in the engine compartment. A 219cc, four stroke, single cylinder spark ignition engine was used. No modifications were required in the engine design as HHO was used as a fuel supplement. The production of HHO was accomplished by the electrolysis of double distilled water in the presence of KOH(aq.) as an electrolyte. Products of water electrolysis consisted of H2 and O2 in the ratio of 2:1 by volumetric basis. Performance enhancement in overall engine characteristics such as brake power, specific fuel consumption, and overall efficiency was observed. Furthermore, a significant reduction in the emissions of unburnt hydrocarbons, carbon monoxide, and carbon dioxide was noticed. However, due to lean air-fuel mixture and tremendous peak combustion temperature the amount of NOx was increased.

Design and Analysis of Exhaust System for Ultra-fuel Efficient Vehicles

Exhaust systems for Internal Combustion (I.C) engines have been finding their significance in the performance of an engine from its inception. One of the detrimental factors for the performance of exhaust is the amount of backpressure building through the flow. This study focuses on reducing backpressure occurring in the exhaust and increasing the ease of manufacturability for a 50 cm3 single cylinder Spark Ignition (S.I.) engine used in an ultra-fuel efficient vehicle. The flow of the exhaust gases from the engine are analyzed with the help of ram induction theory. Computational Fluid Dynamics has been employed to facilitate the study of turbulent flow in the exhaust and obtain results close to a streamlined flow. Parameters such as dimensions, operating pressures and velocities are calculated to understand the flow characteristics. The results strengthen the bilateral scopes of study here being, smooth flow of exhaust gases and greater manufacturability. The bend and end cone angles are defined in such a way that the wastage of material is least and complexity of the geometry is moderate. The exhaust has been designed keeping the chassis and engine complacency constraints in concern. The results of this study can be useful in manufacturing and integration with light gasoline engines, but of the same orientation as the one discussed here, for prototyping purposes.

Yakıt olarak benzin ve LPG kullanılan buji ateşlemeli bir motorun simülasyonu ve performans analizi

Bu çalışmada sonlu zaman termodinamiği metodu kullanılarak buji ateşlemeli motorlarda kullanılmak üzere, Otto çevrimi için bir simülasyon modeli oluşturulmuştur. Simülasyon modelinde, logaritmik bir fonksiyona göre özgül ısıların sıcaklığa bağlı değiştiği, çevrim başlangıç sıcaklığının artık gaz sıcaklığının etkisi ile ortam sıcaklığından yüksek olduğu, sıkıştırma genişleme süreçlerinde tersinmezliklerin olduğu ve ısı, yanma ve sürtünme kayıplarının olduğu, çalışma maddesinin yakıt-hava-artık gaz karışımından oluştuğu kabul edilmiştir. Sıkıştırma oranı, eşdeğerlik oranı ve strok/çap oranının motor performansına etkisi detaylı olarak incelenmiştir. Performans analizi için ısıl verim, özgül yakıt tüketimi, özgül yakıt maliyeti ve güç yoğunluğu kullanılmıştır. Ayrıca motorda LPG kullanıldığında hacimsel verimin azaldığı kabul edilmiştir. Motor ısı balansı için performans kaybı faktörleri kullanılmıştır. Tek silindirli buji ateşlemeli bir motorun özellikleri referans olarak simülasyonda kullanılmıştır. Yapılan kapsamlı sayısal çalışma neticesinde, LPG kullanımında hacimsel verimin %10 azaldığı kabul edildiğinde güç yoğunluğunun %12 azaldığı görülmüştür. LPG’nin özgül yakıt tüketimi benzine göre yüksek olmasına rağmen LPG/benzin fiyat oranı nedeniyle LPG’nin özgül yakıt maliyeti benzine göre oldukça düşük olmaktadır. Sıkıştırma oranının artmasıyla ve strok/çap oranının azalmasıyla birlikte performans kayıpları azalmaktadır. Ayrıca eşdeğerlik oranı 1’den büyük olduğunda performans kayıpları artmaktadır. LPG’nin performans düşüklüğü özellikle hacimsel verimin artırılması veya sıkıştırma oranının artırılmasıyla bertaraf edilebileceği görülmektedir. LPG/benzin fiyat oranı 0,54 olduğunda LPG ile çalışan motorun benzin ile çalışmasına kıyasla %24 daha ekonomik olduğu belirlenmiştir. LPG/benzin fiyat oranı 0,67 olduğunda ise LPG’nin ekonomik avantajının olmadığı görülmüştür. Bu çalışmayla birlikte özellikle motor tasarımcıları için önemli sonuçlar elde edilmiştir.

Mode Strategy for Engine Efficiency Enhancement by Using a Magneto-Rheological Variable Valve Train

Abstract Variable valve timing (VVT) and variable valve lift (VVL) are two promising methods for improving gasoline engine performance. VVL improves part-load performance, and VVT reduces low-speed fuel consumption. Automobile industries and researchers have developed several mechanical, hydraulic, and electronic devices to implement these variable valve functions in engines. In this study, a control strategy is developed for a new compact and low-energy-consumption magneto-rheological valve train (MRVT) to effectively accomplish the variable valve functions and achieve superior engine performance. A non-throttle single-cylinder spark-ignition (SI) engine dynamic model is established to simulate the engine performance by using the flexibility of this new valve train. A six-mode strategy using VVT and VVL is proposed under different engine running conditions of speed and load. Dynamic simulations were conducted for investigating the six-mode strategy based engine performance. The results indicate that the combination of VVT and VVL in the corresponding engine mode can effectively give about 15–20% improvement in the brake fuel efficiency during low and medium speeds. Moreover, by using VVL, about 10–14% improvement in brake specific fuel consumption can be achieved at part-load conditions. According to this computational investigation, the overall engine efficiency and performance can be improved significantly by using a controllable magneto-rheological valve and strategically changing the engine VVL and VVT.

Experimental investigation on ammonia combustion behavior in a spark-ignition engine by means of laminar and turbulent expanding flames

Ammonia combustion appears as a meaningful way to retrieve stored amounts of excess variable renewable energy, and the spark-ignition (SI) engine has been proposed as a practical conversion system. The present work aims at elucidating the combustion characteristics of ammonia blends in engine-relevant turbulent conditions. To that end, laminar and turbulent flame experiments were conducted in a constant-volume vessel at engine-relevant conditions of 445 K and 0.54 MPa to assess the combustion behavior of ammonia/hydrogen/air, ammonia/methane/air and methane/hydrogen/air mixtures observed in an all-metal single-cylinder SI engine. Results show that the respective accelerating or decelerating effects of hydrogen or methane enrichment observed in the SI engine could not be sufficiently explained by the measured laminar burning velocities of the mixtures. Since the latter are very low, the studied combustion regimes are at the boundary between the thin and broken reaction zones regimes, and thus strongly influenced by flame-turbulence interactions. The quantification of the flame response to turbulence shows much higher effects for ammonia blends, than for methane-based fuels. The aforementioned opposite effects of ammonia enrichment with hydrogen or methane are observed on the turbulent burning velocity during the turbulent flame experiments and correlated to the thermochemical properties of the reactants and the flame sensitivity to stretch. The latter may explain an unexpected bending effect on the turbulent-to-laminar velocity ratio when increasing the hydrogen fraction in the ammonia/hydrogen blend. Nevertheless, a very good correlation of the turbulent velocity was found with the Karlovitz and Damköhler numbers, that suggests that ammonia combustion in SI engines may be described following the usual turbulent combustion models. This encourages further investigations on ammonia combustion for the optimization of practical systems, by means of dedicated experiments and numerical simulations.

Analysis of the combustion process in a lean-burning turbulent jet ignition engine fueled with methane

Recent needs of reducing pollutant emissions of internal combustion engines have pushed the development of non-conventional ignition systems. One of the most promising techniques appears to be the so-called Turbulent Jet Ignition (TJI) system, in which a jet of high-energy reactive gases is generated by means of a pilot combustion in a pre-chamber and used to initiate the main combustion event in the cylinder. Considering the complex nature of some phenomena typical of TJI systems, 3D CFD studies are essential to provide a detailed analysis for an efficient design. In this study, numerical simulations of an active pre-chamber TJI system applied to a lean operating methane engine were performed to provide a thorough analysis of the combustion process that characterizes such a technology. The numerical model was validated against experimental measurements carried out on an optically accessible single cylinder spark-ignition engine equipped with the pre-chamber prototype. The numerical simulations provided an insight view of both physical and chemical phenomena occurring inside the pre-chamber otherwise difficult to achieve by experiments alone. The evolution of some species of interest was analyzed in order to study the main charge ignition process, as well as the overall combustion progress. The results show that the main charge ignition is made possible by the large amount of energy and active radicals released from the pre-chamber and this ensures an overall stable and faster combustion in lean conditions. The performance improvements of the TJI system with respect to a traditional spark-ignition engine were evaluated in terms of efficiency and pollutant emission levels.