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Viewing 1 to 30 of 1267
2017-11-05
Technical Paper
2017-32-0054
Iman Kartolaksono Reksowardojo, Phonethip Trichanh, Kevin Ferdyamin, Mega Zulfikar Akbar
This research aims to investigate the effect of ethanol blends with pure gasoline to the rate of fuel consumption and emissions of fuel injection motorcycle 115 cc with automatic transmission which is the population is dominant in Indonesia. Variations of the bioethanol mixture are 0%, 5%, 10%, and 20% ethanol. The experiment conducted in two different conditions by using three ways catalytic converter (TWC) in the exhaust pipe and without using TWC in the exhaust pipe. First, all engine setting was originally manufacture setting. Second, the AFR is set in stoichiometry condition (λ = 1) and ignition timing set in MBT timing using modified ECU. The experiment performed on the chassis dynamometer and referred on the standard cycle ECE 15. The results of this experiment showed that increment of ethanol content in the fuel makes the rate of fuel consumption and CO2 emission both increased but CO and HC emissions decreased.
2017-11-05
Technical Paper
2017-32-0087
Sangriyadi Setio, Wiranto Arismunandar, Rudy Ong, Adefrid Dwithama, Stefanus Adrian, Angela Claudia, Nu’man Amri Maliky, Jery Octavianus, Muhammad Alif Mabbrur, Michell Tjhoi
Developing and designing fuel efficient vehicle for a one gallon of fuel marathon is a challenging task. Engines have to be optimized to achieve maximum fuel efficiency. In this study, we evaluate the optimal compression ratio (CR) and ignition timing that produce the best torque in a custom gasoline-based-motorcycle-engine that use ethanol E100 fuel. In the first experiment, CR was adjusted between 9 and 12 to evaluate its effect on the engine mileage’s record. The experiment was conducted on the test track. In the second experiment, Ignition timing was adjusted by a custom-made engine control unit (ECU) between 15° and 45° before top dead center (BTDC). The engine performance was investigated in terms of best torque and brake specific fuel consumption (BSFC), with variation of engine speed between 1500 and 8000. The test was conducted on dynamometer. The test was also performed in constant compression ratio and stoichiometric air-fuel ratio, 9.
2017-11-05
Technical Paper
2017-32-0088
Hikaru Yamada, Koji Yoshida
The purpose of this study is to explore an effect of the coconut oil methyl ester (CME) and vegetable oil methyl ester (VME) on a low compression ratio diesel engine performance. CME and VME were produced from coconut oil and vegetable oil with methanol, respectively. Vegetable oil was assumed to contain 60 wt.% of soybean oil and 40 wt.% rapeseed oil. The engine performance was measured in the steady operating condition at 3600 rpm of engine speed. The ignition timings of CME and VME were advanced and the maximum cylinder pressures of CME and VME were higher as compared with the diesel fuel at low compression ratio, because CME and VME consisted of medium chain fatty acid methyl esters. The ignitability of CME was superior to VME, because CME consisted of saturated fatty acid. The brake thermal efficiency of diesel fuel was slightly higher than CME and VME at any compression ratios.
2017-11-05
Technical Paper
2017-32-0092
S. Di Iorio, A. Irimescu, S.S. Merola, P. Sementa, B. M. Vaglieco
It is well known that ethanol can be used in spark-ignition (SI) engines as a pure fuel or blended with gasoline. High enthalpy of vaporization of alcohols can affect air-fuel mixture formation prior to ignition and may form thicker liquid films around the intake valves, on the cylinder wall and piston crown. These liquid films can result in mixture non-homogeneities inside the combustion chamber and hence strongly influence the cyclic variability of early combustion stages. Starting from these considerations, the paper reports an experimental study of the initial phases of the combustion process in a single cylinder SI engine fueled with commercial gasoline and anhydrous ethanol, as well as their blend (50%vol alcohol). The engine was optically accessible and equipped with the cylinder head of a commercial power unit for two-wheel applications, with the same geometrical specifications (bore, stroke, compression ratio).
2017-11-05
Technical Paper
2017-32-0095
Preechar Karin, Warawut Amornprapa, Phiranat Khamsrisuk, Pol-ake Budsayahem, Pattara Chammana, Kobsak Sriprapha, Katsunori Hanamura
The soot contamination in used engine oils of diesel engine vehicles was about 1% by weight. The soot and metal wear particle sizes might be in the range of 0-1 µm and 1-25 µm, respectively. The characteristics of soot affecting on metal wear was investigated. Soot particle contamination in diesel engine oil was simulated using carbon black. Micro-nanostructure of soot particles were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and laser diffraction spectroscopy (LDS). The metal wear behavior was studied by means of a Four-Ball tribology test with wear measured. Wear roughness in micro-scale was investigated by high resolution optical microscopy (OM) , 3D rendering optical technique and SEM image processing method. It was found that the ball wear scar diameter increased proportionally to the soot primary particle size. The effect of biodiesel contamination were also increasing in wear scar diameter.
2017-11-05
Technical Paper
2017-32-0094
Preechar Karin, Park Watanawongskorn, Jiramed Boonsakda Eakkawut Saenkhumvong, Sippakorn Rungsritanapaisan, Settavit Srivarocha, Chinda Charoenphonphanich, Nuwong Chollacoop, Katsunori Hanamura
Diesel engines are high thermal efficiency because of high compression ratio but produce high concentration of particulate matter (PM) because of direct injection fuel diffusion combustion. PM must be removed from the exhaust gas to protect human health. This research describes biodiesel engine performance, efficiency and combustion behavior using combustion pressure analyzer. It was clearly observed that PM emitted from CI engines can be reduced by using renewable bio-oxygenated fuels. The morphology and nanostructure of fossil fuel and biofuel PMs were investigated by using a Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The morphology of biodiesel and diesel doesn’t have much different in the viewpoint of particulate matter trapping using DPF micro surface pores. The agglomerated ultrafine particles and primary nanoparticles sizes of diesel and biodiesel engine’s PM are approximately 50-500 nm and 20-50 nm, respectively.
2017-11-05
Technical Paper
2017-32-0101
K. Thammakul, C. Charoenphonphanich, H. Kosaka, M. Tongroon
Primary energy source such as fossil fuel keep decreasing due to various kind of usage. According to less amount of the fossil fuel, human seeks for an alternative fuel source such as alcohol. Alcohol like ethanol can be produced easily from strarchy plant. But using alcohol as blended fuel with diesel fuel doesn't work well because alcohol has low cetane number, lack of lubricity and very low miscibility with diesel fuel. To overcome this, fumigation system or port fuel injection of alcohol seems interesting. Although it requires more complicate system but it can compensate the miscibility issue and alcohol can be used in higher dose to give more energy. Diesel engine produces a lot of emission such as NOx and some other carbon content emission like HC, CO and soot due to they run in lean condition as their characteristic. Modern diesel engines are now coupled with exhaust gas recirculation system to help reduce in main emission like NOx.
2017-11-05
Technical Paper
2017-32-0103
T. Painrungrot, C. Charoenphonphanich, H. Kosaka, M. Tongroon
Ethanol is a good choice for alternative fuel which is prefer to dual fuel diesel engine. In this study, ethanol will be injected in to the intake manifold to cool down the intake temperature and reduce the amount of diesel fuel consumption. And also, use a technique called internal exhaust gas recirculation. The exhaust valve will be reopened during the intake stroke for 4mm. to vaporized the injected ethanol in the combustion chamber. The objective of this research is to study the effect of injection timing of dual fuel (diesel) on the engine performance and exhaust emissions of a supercharged, single cylinder 4-stroke direct injection compression ignition engine including ethanol fumigation and internal EGR, and also varying the injection pressure of diesel. Then using ethanol fuel as a secondary fuel to replace the energy input from diesel fuel by 10, 20, and 30%.
2017-11-05
Technical Paper
2017-32-0070
Stephan Jandl, Patrick Pertl, Hans-Juergen Schacht, Stephan Schmidt, Stefan Leiber
The development of future internal combustion engines and fuels is influenced by decreasing energy resources, restriction of emission legislation and increasing environmental awareness of humanity itself. Alternative renewable fuels have, in dependency on their physical and chemical properties, on the production process and on the raw material, the potential to contribute a better well-to-wheel-CO2-emission-balance in automotive and nonautomotive applications. The focus of this research is the usage of alcohol fuels, like ethanol and 2-butanol, in motorcycle high power engines. The different propulsion systems and operation scenarios of motorcycle applications in comparison to automobile applications raise the need for specific research in this area.
2017-10-08
Technical Paper
2017-01-2340
Shashank Mishra, Anand Krishnasamy
Abstract Biodiesel is a renewable, carbon neutral alternative fuel to diesel for compression ignition engine applications. Biodiesel could be produced from a large variety of feedstocks including vegetable oils, animal fats, algae, etc. and thus, vary significantly in their composition, fuel properties and thereby, engine characteristics. In the present work, the effects of biodiesel compositional variations on engine characteristics are captured using a multi-linear regression model incorporated with two new biodiesel composition based parameters, viz. straight chain saturation factor (SCSF) and modified degree of unsaturation (DUm). For this purpose, biodiesel produced from seven vegetable oils having significantly different compositions are tested in a single cylinder diesel engine at varying loads and injection timings. The regression model is formulated using 35 measured data points and is validated with 15 other data points which are not used for formulation.
2017-10-08
Technical Paper
2017-01-2339
Pi-qiang Tan, Yuan Li
Abstract With increasingly severe atmospheric environmental problems, diesel car emissions have attracted broad attention for its main contribution to air pollutant. Alternative fuels become a hot research point in vehicle for rapidly consuming of fossil oil resources. Biodiesel and GTL (gas to liquid) fuels are two typical alternative fuels for diesel fuel. Low blend ratio (≤10%) biodiesel and GTL fuels can be used in a diesel engine without modifying the engine’s configuration. It is important to investigate the difference of low blend ratio biodiesel and GTL fuels used in the same diesel car and to find the optimum one. Gaseous and particle emissions from a light duty diesel car with B10 (10% biodiesel from cooking oil +90% diesel, v/v) and G10 (10% GTL fuel +90% diesel, v/v) was investigated. It was equipped with high pressure common rail system, cooled EGR and DOC and was tested on a chassis dynamometer under NEDC mode.
2017-10-08
Technical Paper
2017-01-2327
Joonsik Hwang, Choongsik Bae, Chetankumar Patel, Avinash Kumar Agarwal, Tarun Gupta
Abstract Fuel atomization and air-fuel mixing processes play a dominant role on engine performance and emission characteristics in a direct injection compression ignition engine. Understanding of microscopic spray characteristics is essential to predict combustion phenomena. The present work investigated near nozzle flow and atomization characteristics of biodiesel fuels in a constant volume chamber. Waste cooking oil, Jatropha, and Karanja biodiesels were applied and the results were compared with those of conventional diesel fuel. The tested fuels were injected by a solenoid injector with a common-rail injection system. A high-speed camera with a long distance microscopic lens was utilized to capture the near nozzle flow. Meanwhile, Sauter mean diameter (SMD) was measured by a phase Doppler particle analyzer to compare atomization characteristics.
2017-10-08
Technical Paper
2017-01-2326
Ang Li, Zhiwei Deng, Lei Zhu, Zhen Huang
Abstract In the present study a novel surrogate model for biodiesel including methyl decanoate (MD) and methyl crotonate (MC) was proposed and validated. In the binary mixture of surrogate fuel, MD was chosen to represent saturated methyl esters, which exhibited great low-temperature reactivity with typical negative temperature-coefficient (NTC) behavior and MC represented unsaturated components in real biodiesel, which was mainly responsible for soot formation and evolution. The proportion of MD and MC was determined by matching the characteristics such as derived cetane number (DCN), molecular weight (MW), atom number, H/C ratio and unsaturated degree. All of the criterions were calculated by the least square principles and the calculated surrogate of biodiesel was comprised of 92% MD and 8% MC in mole fraction. Furthermore, detailed kinetic model of the surrogate fuel was constructed and developed with modifications, which was composed of 2918 species and 9164 reactions.
2017-10-08
Technical Paper
2017-01-2331
Amar Deep, Naveen Kumar, Harveer Singh Pali
Abstract The use of alternative fuel has many advantages and the main ones are its renewability, biodegradability with better quality exhaust gas emission, which do not contribute to raise the level of carbon dioxide in the atmosphere. The use of non-edible vegetables oils as an alternative fuels for diesel engine is accelerated by the energy crisis due to depletion of resources and increase in environmental problems. In Asian countries like India, great need of edible oil as a food so cannot use these oils as alternative fuels for diesel engine. However there are many issues related to the use of vegetable oils in diesel engine that is high viscosity, low calorific value, high self-ignition temperature etc. Jatropha curcas has been promoted in India as a sustainable substitute to diesel fuel. This research prepared micro emulsions of ethanol and Jatropha vegetable oil in different ratio and find out the physico-chemical parameters to compare with mineral diesel oil.
2017-10-08
Technical Paper
2017-01-2330
Leonardo Israel Farfan-Cabrera, Ezequiel Gallardo, José Pérez-González
Abstract Flouroelastomers and silicone rubbers are commonly employed in static and dynamic seals for automotive applications. In order to prevent premature failures and leakages caused by swelling and/or changes in their mechanical properties, materials for seals are selected according to their compatibility with the environment and fluids involved in the engine operation. Thus, in particular, the use of new fuels and additives in automotive engines requires the assessment of compatibility with common sealing elastomers to prevent failures. Currently, Jatropha oil is being used as a renewable source of fuel in diesel engines for electricity production, transport or agricultural mechanization in various countries. It is used either as biodiesel or as straight vegetable oil (SVO) since it has good heating power and provide exhaust gas with almost no sulfur or aromatic polycyclic compounds. However, the compatibility of elastomers with this SVO has not been investigated yet.
2017-10-08
Technical Paper
2017-01-2332
Tamara Ottenwaelder, Stefan Pischinger
Abstract In order to reduce engine out CO2 emissions it is a main subject to find new alternative fuels out of renewable sources. For this paper, several fuels were selected which can be produced out of biomass or with hydrogen which is generated directly via electrolysis with electricity from renewable sources. All fuels are compared to conventional diesel fuel and two diesel surrogates. It is well known that there can be a large effect of fuel properties on mixture formation and combustion, which may result in a completely different engine performance compared to the operation with conventional diesel fuels. Mixture formation and ignition behavior can also largely affect the pollutant formation. The knowledge of the combustion behavior is also important to design new engine geometries or implement new calibrations for an existing engine. The fuel properties of the investigated fuels comprise a large range, for example in case of the derived cetane number, from below 30 up to 100.
2017-10-08
Technical Paper
2017-01-2397
Zhan Gao, Lei Zhu, Xinyao Zou, Chunpeng Liu, Zhen Huang
Abstract Biodiesel is a potential alternative fuel which can meet the growing need for sustainable energy. Partially premixed compression ignition (PPCI) is an important low-temperature combustion strategy to reduce NOx and soot emission of diesel engines. To investigate partial premixing impact on particle formation in flames of biodiesel or biodiesel surrogates, an experimental study was performed to compare the soot morphology and nanostructure evolution in laminar co-flow methyl decanoate non-premixed flame (NPF) and partially premixed flame (PPF). The thermophoretic sampling technique was used to capture particles along flame centerlines. Soot morphology information and volume fraction were obtained from TEM analysis and nanostructure features were evaluated by HR-TEM. With primary equivalence ratio of 19, gas temperature of PPF is higher along flame centerline compared with NPF. The results show an initially stronger sooting tendency in PPF at lower positions.
2017-10-08
Technical Paper
2017-01-2396
Fushui Liu, Yang Hua, Han Wu, Xu He, Ning Kang
Abstract Soot emission, known as PM (particulate matter), is becoming a big issue for GDI engines as the emission regulations being increasingly stricter. It is found that ethanol, as an oxygenated bio-fuel, can reduce the soot emission when added to gasoline. In order to fully understand the effect of ethanol on soot reducing, the soot characteristics of ethanol/gasoline blends were studied on laminar diffusion flames. In this experiment, the blending ratio of ethanol/gasoline was set as E0/20/40/60/80. Considering the carbon content decreasing due to ethanol addition, carbon mass flow rate was remained constant. The two-dimensional distributions of soot volume fraction were measured quantitatively by using two-color laser induced incandescence technique. The results showed that ethanol is able to decrease the soot significantly, but the effect of ethanol on soot reduction is weakened with the increasing ethanol ratio.
2017-10-08
Technical Paper
2017-01-2382
Tul Suthiprasert, Sirichai Jirawongnuson, Ekathai Wirojsakunchai, Tanet Aroonsrisopon, Krisada Wannatong, Atsawin Salee
Abstract The diesel dual fuel engine emits CH4 in the exhaust gas. This makes the exhaust gas more difficult to treat comparing to the exhaust gas from the conventional engine since CH4 requires high exhaust temperature to oxidize. In addition, another parameter such as exhaust flow rate, specie concentrations, especially CO, C3H8, and H2O have tremendous impact on Diesel Oxidation Catalyst performance on reducing CH4. This research is aimed to propose a kinetic model based on Langmuir Hinshelwood mechanisms that includes several terms such as CH4, C3H8, CO, O2, and H2O concentrations in order to gain a better understanding on the catalytic reaction and to provide a simulation with an accurate prediction. The model’s kinetic parameters are determined from the experiment by using synthetic gas. The composition of synthetic gas is simulated to be similar to the real exhaust gas from diesel dual fuel engines.
2017-10-08
Technical Paper
2017-01-2390
Hongxue Zhao, Daliang Jing, Yinhui Wang, Shi-jin Shuai, Changle PANG
Abstract In this paper, the impacts of Aromatic and Olefin on the formation of poly-aromatic hydrocarbons (PAHs) in the gasoline direct injection (GDI) engine were experimentally and numerically investigated. The objective of this study is to describe the formation process of the soot precursors including one ring to four ring aromatics (A1-A4). In order to better understand the effects of the fuel properties on the formations of PAHs. Three types of fuels, namely base gasoline, gasoline with higher aromatics content, and gasoline with higher olefin content were experimentally studied. At the same time, these aspects were also numerically investigated in the CHEMKIN code by using premixed laminar flame model and surrogated fuels. The results show that higher aromatics content in gasoline will lead to much higher PAHs formation. Similar trend was also found in the gasoline with higher olefin content.
2017-10-08
Technical Paper
2017-01-2186
Lukas Urban, Michael Grill, Sebastian Hann, Michael Bargende
Abstract Engine Knock is a stochastic phenomenon that occurs during the regular combustion of spark ignition (SI) engines and limits its efficiency. Knock is triggered by an autoignition of local “hot spots” in the unburned zone, ahead of the flame front. Regarding chemical kinetics, the temperature and pressure history as well as the knock resistance of the fuel are the main driver for the autoignition process. In this paper, a new knock modeling approach for natural gas blends is presented. It is based on a kinetic fit for the ignition delay times that has been derived from chemical kinetics simulations. The knock model is coupled with an enhanced burn rate model that was modified for Methane-based fuels. The two newly developed models are incorporated in a predictive 0D/1D simulation tool that provides a cost-effective method for the development of natural gas powered SI engines.
2017-10-08
Technical Paper
2017-01-2191
Yachao Chang, Ming Jia, Yanzhi Zhang, Yaopeng Li, Weiwei Fan, MaoZhao Xie
Abstract Dimethyl ether (DME) attracts increasing attentions in recent years, because it can reduce the carbon monoxide (CO), unburned hydrocarbon (HC), and soot emissions for engines as the transportation fuel or the fuel additive. In this paper, a reduced DME oxidation mechanism is developed using the decoupling methodology. The rate constants of the fuel-related reactions are optimized using the non-dominated sorting genetic algorithm II (NSGA-II) to reproduce the ignition delay times in shock tubes and major species concentrations in jet-stirred reactors (JSR) over low-to-high temperatures. In NSGA-II, the range of the rate constants was considered to ensure the reliability of the optimized mechanism. Moreover, an improved objective function was proposed to maintain the faithfulness of the optimized mechanism to the original reaction mechanism, and a new method was presented to determine the optimal solution from the Pareto front.
2017-10-08
Technical Paper
2017-01-2192
Shenghui Zhong, Zhijun Peng, Yu Li, Hailin Li, Fan Zhang
Abstract A 3-D DNS (Three-Dimensional Direct Numerical Simulation) study with detailed chemical kinetic mechanism of methane has been performed to investigate the characteristics of turbulent premixed oxy-fuel combustion in the condition relevant to Spark Ignition (SI) engines. First, 1-D (one-dimensional) laminar freely propagating premixed flame is examined to show a consistent combustion temperature for different dilution cases, such that 73% H2O and 66% CO2 dilution ratios are adopted in the following 3-D DNS cases. Four 3-D DNS cases with various turbulence intensities are conducted. It is found that dilution agents can reduce the overall flame temperature but with an enhancement of density weighted flame speed. CO2 dilution case shows the lowest flame speed both in turbulent and laminar cases.
2017-10-08
Technical Paper
2017-01-2193
Andreas Nygren, Anders Karlsson
Abstract When developing new combustion concepts, CFD simulations is a powerful tool. The modeling of spray formation is a challenging but important part when it comes to CFD modelling of non-premixed combustion. There is a large difference in the accuracy and robustness among different spray models and their implementation in different CFD codes. In the work presented in this paper a spray model, designated as VSB2 has been implemented in OpenFOAM. VSB2 differ from traditional spray models by replacing the Lagrangian parcels with stochastic blobs. The stochastic blobs consists of a droplet size distribution rather than equal sized droplets, as is the case with the traditional parcel. The VSB2 model has previously been thoroughly validated for spray formation and combustion of n-heptane. The aim of this study was to validate the VSB2 spray model for ethanol spray formation and combustion as a step in modelling dual-fuel combustion with alcohol and diesel.
2017-10-08
Technical Paper
2017-01-2230
Nizar F.O. Al-Muhsen, Guang Hong
Abstract Ethanol as a renewable fuel has been used widely in vehicles. Dual fuel injection is one of the new techniques in development for increasing the engine’s thermal efficiency and reducing the pollutant emissions. This study reports experimental investigation to the dual ethanol fuel injection with a focus on the effect of spark timing on the engine performance at different volumetric ratios of ethanol directly injected to ethanol port injected. Experiments were conducted on a single cylinder 250cc spark ignition engine at two engine loads and 3500 RPM. The spark timing was varied from 15 to 42 CAD bTDC at the light load and from 15 to 32 CAD bTDC at the medium load, while the volumetric ratio of direct injection (DI%) was varied from 0% to 100%.
2017-10-08
Technical Paper
2017-01-2238
Ripudaman Singh, Travis Burch, George Lavoie, Margaret Wooldridge, Mohammad Fatouraie
Abstract Numerous studies have demonstrated the benefits of ethanol in increasing the thermal efficiency of gasoline-fueled spark ignition engines via the higher enthalpy of vaporization and higher knock resistance of ethanol compared with gasoline. This study expands on previous work by considering a split fuel injection strategy with a boosted direct injection spark ignition engine fueled with E0 (100% by volume reference grade gasoline; with research octane number = 91 and motor octane number = 83), E100 (100% by volume anhydrous ethanol), and various splash-blends of the two fuels. Experiments were performed using a production 3-cylinder Ford Ecoboost engine where two cylinders were de-activated to create a single-cylinder engine with a displacement of 0.33 L. The engine was operated over a range of loads with boosted intake manifold absolute pressure (MAP) from 1 bar to 1.5 bar.
2017-10-08
Technical Paper
2017-01-2256
Muhammad Umer Waqas, Kai Morganti, Jean-Baptiste Masurier, Bengt Johansson
Abstract The blending behavior of ethanol in five different hydrocarbon base fuels with octane numbers of approximately 70 and 84 was examined under Spark-Ignited (SI) and Homogeneous Charge Compression Ignited (HCCI) operating conditions. The Blending octane number (BON) was used to characterize the blending behavior on both a volume and molar basis. Previous studies have shown that the blending behavior of ethanol generally follows several well-established rules. In particular, non-linear blending effects are generally observed on a volume basis (i.e. BON > RON or MON of pure ethanol; 108 and 89, respectively), while linear blending effects are generally observed on a molar basis (i.e. BON = RON or MON of pure ethanol). This work firstly demonstrates that the non-linear volumetric blending effects traditionally observed under SI operating conditions are also observed under HCCI operating conditions.
2017-10-08
Technical Paper
2017-01-2268
Zhanming Chen, Long Wang, Tiancong Zhang, Qimeng Duan, Bo Yang
Abstract Engines fuelled with Liquefied natural gas (LNG) have been widely used in the heavy-duty vehicles. However, they suffer from poor combustion performance and flame instability under fuel-lean condition. In this work, experiments were performed on a turbo-charged, spark-ignition engine fuelled with natural gas (NG) and methanol. The combustion characteristics such as in-cylinder pressure, heat release rate (HRR), burned mass fraction (BMF), ringing/knock intensity (RI), ignition delay, centroid of HRR, and coefficient of variation (COV) of indicated mean effective pressure (IMEP) were analyzed under light load (brake mean effective pressure=0.3876 MPa) with different methanol substitution rates (MSR=0%, 16%, 34%, 46%). The experimental results showed that combustion phase advanced with the increase in MSR due to faster burning velocity of methanol. Knock only occurred at MSR=46%, 2000 rpm.
2017-10-08
Technical Paper
2017-01-2269
Shijun Dong, Xiaobei Cheng, Biao Ou, Can Yang, Zhaowen Wang, Fumin Pan
Abstract Based on a composed PRF/ethanol/PAH mechanism, simulations were conducted to investigate the combustion characteristics of n-heptane spray under premixed ethanol/air and iso-octane/air atmosphere in a combustion vessel. The effects of premixed ethanol and iso-octane on ignition delay, important soot precursors and soot volume fraction of n-heptane spray were studied. Also, simulated results with and without considering the cooling effects of premixed fuel vaporization were compared. When the cooling effect of premixed fuel vaporization was not considered, simulations showed that premixed ethanol could increase the ignition delay of n-heptane spray at ambient temperatures below 850K. However, premixed iso-octane showed little inhibition effect on ignition of n-heptane spray. Also, it was found that both premixed ethanol and iso-octane contributed to faster ignition under high ambient temperatures.
2017-10-08
Technical Paper
2017-01-2278
Zhiwei Deng, Ang Li, Lei Zhu, Zhen Huang
Abstract In-cylinder thermochemical fuel reforming (TFR) in spark ignition natural gas engine was developed to reveal that thermochemical fuel reforming could increase H2 and CO concentration in reformed gas, leading to an increase of thermal efficiency and engine performance. Moreover, ethanol enrichment has been proved to have great potential to optimize TFR performance. In order to explain TFR phenomenon chemically, methane oxidation experiments were conducted in a laminar flow reactor with addition of ethanol and methanol at equivalent ratios of 1.5, 1.7, 1.9 and 2.1 from 948K to 1098K at atmospheric pressure. Experimental results showed that methanol have great ability to facilitate the oxidation of methane than that of ethanol. Meanwhile, the degree of methane conversion became more significantly as the equivalent ratio increased. Kinetic analysis of oxidation of methane with alcohol enrichment in a plug flow model was also conducted in this study.
Viewing 1 to 30 of 1267