Numerical Simulation of a Spark Ignition Engine Using Liquid Fuels and Liquid Fuel Blends

2003 ◽  
Author(s):  
K. Majmudar ◽  
K. Aung

The use of alternative fuels such as methanol and ethanol in spark-ignition (SI) engines is beneficial to the environment as it reduces emissions of pollutants such as NOx from these engines with slight penalty on the performance. This paper investigated the use of liquid fuel blends such as ethanol/gasoline blend in an SI engine by numerical simulations. The numerical simulations were based on the models of finite heat release, cylinder heat transfer, pumping losses, and friction losses. Simulations were carried out to evaluate the effects of compression ratio, equivalence ratio, ignition timing, and engine speed on the performance of the SI engine. The results of the simulations were compared with experimental data from the literature to validate the simulations. Good agreements between the computed and experimental results were obtained. The results showed that the current model could satisfactorily predict the performance of an SI engine fueled by liquid fuel blends.

Author(s):  
V. Matham ◽  
K. Majmudar ◽  
K. Aung

The use of alternative fuels such as natural gas (methane) in spark-ignition (SI) engines is beneficial to the environment as it reduces emissions of pollutants such as NOx from these engines with slight penalty on the performance. This paper investigated the use of methane and hydrogen/methane mixtures in an SI engine by numerical simulations. The numerical simulations were based on the models of finite heat release, cylinder heat transfer, pumping losses, and friction losses. Simulations were carried out to evaluate the effects of compression ratio, equivalence ratio, ignition timing, and engine speed on the performance of the SI engine. The results showed that the current model could satisfactorily predict the performance of an SI engine fueled by gaseous fuels.


Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi

The operation of spark ignition (SI) engines on lean mixtures is attractive, in principle, since it can provide improved fuel economy, reduced tendency to knock, and extremely low NOx emissions. However, the associated flame propagation rates become degraded significantly and drop sharply as the operating mixture is made increasingly leaner. Consequently, there exist distinct operational lean mixture limits beyond which satisfactory engine performance cannot be maintained due to the resulting prolonged and unstable combustion processes. This paper presents experimental data obtained in a single cylinder, variable compression ratio, SI engine when operated in turn on methane, hydrogen, carbon monoxide, gasoline, iso-octane, and some of their binary mixtures. A quantitative approach for determining the operational limits of SI engines is proposed. The lean limits thus derived are compared and validated against the corresponding experimental results obtained using more traditional approaches. On this basis, the dependence of the values of the lean mixture operational limits on the composition of the fuel mixtures is investigated and discussed. The operational limit for throttled operation with methane as the fuel is also established.


2013 ◽  
Vol 17 (1) ◽  
pp. 119-133 ◽  
Author(s):  
Jovan Doric ◽  
Ivan Klinar

A zero dimensional model has been used to investigate the combustion performance of a four cylinder petrol engine with unconventional piston motion. The main feature of this new spark ignition (SI) engine concept is the realization of quasi-constant volume (QCV) during combustion process. Presented mechanism is designed to obtain a specific motion law which provides better fuel consumption of internal combustion (IC) engines. These advantages over standard engine are achieved through synthesis of unconventional piston mechanism. The numerical calculation was performed for several cases of different piston mechanism parameters, compression ratio and engine speed. Calculated efficiency and power diagrams are plotted and compared with performance of ordinary SI engine. The results show that combustion during quasi-constant volume has significant impact on improvement of efficiency. The main aim of this paper is to find a proper kinematics parameter of unconventional piston mechanism for most efficient heat addition in SI engines.


2021 ◽  
Vol 13 (16) ◽  
pp. 8729
Author(s):  
Michał Wojcieszyk ◽  
Lotta Knuutila ◽  
Yuri Kroyan ◽  
Mário de Pinto Balsemão ◽  
Rupali Tripathi ◽  
...  

Several countries have set ambitious targets for the transport sector that mandate a gradual increase in advanced biofuel content in the coming years. The current work addresses this transition and indicates two promising gasoline bio-blendstocks: Anisole and isobutanol. The whole value chains of these bio-components were considered, focusing on end-use performance, but also analyzing feedstock and its conversion, well-to wheel (WTW) greenhouse gas (GHG) emissions and costs. Three alternative fuels, namely a ternary blend (15% anisole, 15% isobutanol, 70% fossil gasoline on an energy basis) and two binary blends (15% anisole with fossil gasoline and 30% isobutanol with fossil gasoline), were tested, focusing on their drop-in applicability in spark ignition (SI) engines. The formulated liquid fuels performed well and showed the potential to increase brake thermal efficiency (BTE) by 1.4% on average. Measured unburned hydrocarbons (HC) and carbon monoxide (CO) emissions were increased on average by 12–29% and 17–51%, respectively. However, HC and CO concentrations and exhaust temperatures were at acceptable levels for proper catalyst operation. The studied blends were estimated to bring 11–22% of WTW GHG emission reductions compared to base gasoline. Additionally, the fleet performance and benefits of flexi-fuel vehicles (FFV) were modeled for ternary blends.


Bio-fuels have been made vital developments from past decades, in which bio-petrol plays a major role in SI engines. Developments in petrol-ethanol blends have been made to improve the efficiency of SI engine. Air preheated is supported widely in preheating of intake air. To improve efficiency and to reduce emission, air preheated is used in many systems. SI engines are used in automobiles, motor cycles, aircrafts, motorboats and portable small engine. In this work, investigations have been done in the SI engine which intakes preheated air-fuel mixture and various blends of ethanol petrol fuel is used as working fuel. Emission tests are done by exhaust gas analyzer to compare the emissions of different fuels.


Author(s):  
M. Z. Haq ◽  
A. Morshed

The paper presents energy and exergy based analyses of a single cylinder, four-stroke, spark ignition engine fuelled by six different fuels namely iso-octane, methane, hydrogen, methanol, ethanol and n-butanol. Wiebe function is used to predict realistic burn rates. Since the Wiebe function parameters are generally optimized for conventional fuels, the current study modifies them for different alternative fuels using available burning velocity data. Heat losses throughout the cycle have been predicted by empirical correlations. Analyses are carried out to quantify energy and exergy of the premixed fuel-air mixture inside the engine cylinder at various phases of the cycle and some results obtained from the study are validated against data available in literature. Both energy and exergy destructions are found to be dependent on the fuels and engine operating parameters. Results show that at 1000 rpm, about 34–39% of energy contained in the fuel is converted into useful work and this quantity is found to increase with engine speed. Exergies associated with exhaust are found significantly lower than the corresponding energy values for all fuels. The present study highlights the necessity of both energy and exergy analyses to probe and identify the sources of work potential losses in SI engines in various phases of the cycle.


2021 ◽  
Author(s):  
Jim Alexander ◽  
E Porpatham

Abstract The implementation of recent emission norms has caused the automotive industries to develop advanced technologies for gaseous fuelled SI engines. This research focused on the comparison of turbocharged Compression Ratio (CR) 10.5:1 and naturally aspirated (NA) 12.5:1 for Compressed Bio-Methane (CBM) fuelled SI engine. The original port fuel injected automotive Compressed Natural Gas (CNG) Spark Ignition (SI) engine with 15.5 kW at 3400 rpm was made to function with CBM fuel under full throttle conditions at given CR. Also, two turbochargers T1 and T2 were analysed and validated using ANSYS turbo-machinery numerical package. T1 generated a higher-pressure ratio than T2 and was preferable. The simulation study outcomes infer that entropy generation for T1 at a 1.3 bar is less than 1.5 bar gave a better transient response. The experimental comparison was made between CR of 10.5:1 turbocharged and naturally aspirated CR of 12.5:1. At CR of 10.5:1, 1.3 bar boost pressure, brake power increased by 19.3%, reduced fuel consumption by 10.1%, and reduced hydro carbon (HC) and Carbon monoxide (CO) emissions 42.9% and 38.3%, when compared to NA CR of 12.5:1. On the whole, the downsized CR of 10.5:1 turbocharging exhibit better performance and reduced thermal loading when compared to higher CR of 12.5:1.


Author(s):  
Ümit Ağbulut ◽  
Mustafa Aydin ◽  
Mustafa Karagöz ◽  
Emrah Deniz ◽  
Burak Çiftçi

Natural gas, biogas and alcohols are alternative fuels for spark ignition engines which can be used for reducing exhaust emissions and improving performance metrics. At the first stage of the study, a pilot scale biogas system was built, and biogas was produced from a mixture of manure and water called slurry, consisting of 40% cattle manure, 35% water, 17% whey and 8% poultry manure by co-fermentation method. Scrubbing and desulfurization were applied to remove the harmful gasses (CO2, H2S) from the produced biogas in two stages. In the end of the purification process, biogas with a CH4 content of 51%, 57% and 87% was produced. In the second stage, these biogas fuels were used in an SI engine, and their impacts on performance and combustion characteristics were investigated experimentally. A 4-cylinder, 4-stroke, water cooled SI engine with an 11:1 compression ratio was used in the experiments. Tests were conducted at various loads and constant speed. Results showed that daily amount of mean biogas production has reached 1.6 m3/day and biogas methane content has reached 72%. In engine tests, as the methane ratio in biogas increases, cylinder pressure and exhaust temperature values increase and brake specific fuel consumption decreases.


RSC Advances ◽  
2014 ◽  
Vol 4 (93) ◽  
pp. 51220-51227 ◽  
Author(s):  
B. M. Masum ◽  
M. A. Kalam ◽  
H. H. Masjuki ◽  
S. M. Ashrafur Rahman ◽  
E. E. Daggig

Like other alcohols, denatured anhydrous ethanol is a promising alternative fuel for SI engine.


2017 ◽  
Vol 2 (3) ◽  
pp. 30 ◽  
Author(s):  
A. Adebayo ◽  
Omojola Awogbemi

This research investigated the effects of addition of ethanol to gasoline with the aim of improving the performance and emission characteristics of Spark Ignition (SI) engine. Four samples of gasoline-ethanol blend were prepared, namely 100% ethanol, 100% gasoline, 95% gasoline + 5% ethanol and 90% gasoline+10% ethanol, and were labeled sample A, B, C and D respectively. Physicochemical analysis was carried out on the four samples while sample B, C, and D were used to run a single cylinder, two stroke, air cooled SI engine to determine the performance characteristics of the engine at four engine speeds of 800rpm, 1000rpm, 1200rpm, and 1400rpm. An exhaust gas analyzer was used to analyze the exhaust emission to determine its constituents at no load. The research concluded that blending gasoline with ethanol not only improved the performance of the engine, it also yielded a friendlier emission. It also solves the problem of sole dependence on petroleum products to run SI engines with its attendant cost and environmental implications.


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