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Viewing 1 to 30 of 324
2017-11-07
Technical Paper
2017-36-0084
Ricardo Gonçalves, Fabio Ferraz
Abstract Currently in Brazilian market we have application of two different fuels in large scale, gasoline with addition of 27% of hydrous ethanol, otherwise known as ethyl alcohol or alcohol and pure hydrous ethanol. These different fuels and their various blends combinations - from 27% (E27) to 100% (E100) of ethanol - make the gases from combustion have different physical characteristics, affecting directly the exhaust system acoustic performance. This study is going to describe the physical differences of the exhaust gases with various blends combination and their respective impact on the exhaust system acoustic performances.
2017-11-07
Technical Paper
2017-36-0147
Clayton B. Zabeu, Luana C. X. Camargos, Luiz Rafael Marinsek, Rafael C. R. Berti, Renan L. Nicola, Rafael Serralvo Neto
Abstract The need to reduce greenhouse gas emissions by the automotive sector has demanded an increase in the efficiency of internal combustion engines as well as the use of renewable fuels, with ethanol being one of the most promising fuels. In SI PFI engines, the quality of the air-fuel mixture formed during the injection event is dependent on several factors, such as: physical-chemical properties of the fuel (density, viscosity, surface tension, latent heat of vaporization), interaction between fuel spray and gas flow / pipe walls / back surfaces the intake valves.
2017-11-07
Technical Paper
2017-36-0388
Fernanda Pinheiro Martins, Santiago Daniel Martinez Boggio, Pedro Texeira Lacava, Claudia Regina de Andrade, Alexander Penaranda, Maycon Ferreira Silva, Maria Esther Sbampato
Abstract In the last few decades a significant effort has been stablished in the automotive industry as well as in academic community towards increasing the renewable fuels applications in internal combustion engines, such as alcohol and gas derived sources. Meanwhile, turbo charging direct-injection spark-ignition engines have become fundamental features to achieve downsizing purposes, increasing power generation efficiency and attending high restrictive emissions regulations that have being taking place recently. For this study, experimental tests were carried out in a single cylinder research engine considering direct injection (DI) and port fuel injection (PFI) operations with anhydrous ethanol. The aim of this paper is to present a review and conduct further investigation about methodologies applied for imaging post processing considering chemiluminescence technique applied in an optical research engine.
2017-11-07
Technical Paper
2017-36-0247
Fernando de Oliveira Junior, Isaac Gentini, Fernando Lepsch, Alex Siegle, Guilherme Torres Ferreira
Abstract The first generation of heated cold start systems for flex fuel vehicles in Brazil were launched in 2009 and have solved most of the issues around the former gasoline sub-tank concept. This new technological approach focused on concerns like the user experience by having the need to fulfill the sub-tank, on complains related to possible old gasoline left inside, in the complexity of the electro mechanic nozzles and other possible improvements. Some years later, the second generation expanded the initial cold start application to a mature drivability enhancement and further possibility of usage as a support for emission reduction. A leaner electronic control and heat sink concept also represented an alternative to the first generation, and an engineered plastic fuel rail replaced the first metallic concept, which was an option to the initial concerns about the combination of high temperatures and fuel.
2017-11-07
Technical Paper
2017-36-0259
Thiago R. V. Silva, José G. C. Baeta, Nilton A. D. Neto, Augusto C. T. Malaquias, Matheus G. F. Carvalho, Fernando R. Filho
Abstract The current energy and climate world condition presents the need for development of increasingly efficient and sustainable internal combustion engines. In order to meet these requirements, environmental regulatory agencies establish long-term goals of fuel consumption and pollutant gases emissions reduction, which in turn lead the engines to a constant evolution. Thus, this work exploits some recent technologies that tend to minimize the environmental impact of the world’s extensive automotive fleet. Among them, direct injection systems, especially with the use of biofuels, such as ethanol, allow the engine to operate under lean stratified conditions through split-injection. This strategy consists to split several times the fuel injection phase, so that an injection portion can be performed at the intake stroke and the other injection portion at the compression stroke.
2017-11-07
Technical Paper
2017-36-0264
Thiago R. V. Silva, José G. C. Baeta, Nilton A. D. Neto, Augusto C. T. Malaquias, Matheus G. F. Carvalho, Fernando R. Filho
Abstract The downsized ethanol Spark Ignited Direct Injection (SIDI) engine has proven to be one of the most promising concepts to reduce both the fuel consumption and pollutant emissions. In addition to this engine concept, the use of Fully Variable Camshaft Timing (FVCT) can provide the Internal Exhaust Gas Recirculation (I-EGR) into the combustion chamber. The Cooled Exhaust Gas Recirculation (Cooled - EGR) technique, has been adopted in order to reduce the NOx formation rate. However, through the FVCT system, acceptable levels of charge dilution by I-EGR can be achieved resulting in less fuel consumption and pollutant emissions. In this paper, the I-EGR technique has been investigated by carrying out an experimental analysis of a downsized ethanol SIDI engine running on boosted and unboosted conditions. The results at part load operation present a gain on fuel conversion efficiency due to the I-EGR dilution and the use of de-throttling technique.
2017-11-07
Technical Paper
2017-36-0272
Victor Hugo de Castro Lima, Carlos Alberto Gomes Júnior, Márcio Expedito Guzzo, Thiago Rodrigo Vieira da Silva, José Guilherme Coelho Baeta, Fernando Antonio Rodrigues Filho
Abstract The growing demand for more efficient and less polluting engines has lead the scientific community to further develop the road map engine technologies, including direct fuel injection. Direct injection research demands the investigation of spray formation and its characteristics. The present work performs the characterization of the macroscopic parameters of ethanol sprays (E100) produced with a fuel gauge pressure of 80 bar and gauge back pressures of 0, 5 and 10 bar. The sprays analysis was performed using high speed filming by means of Shadowgraph technique. Computational routines of matrix analysis were applied to measure the spray cone angles, penetration and penetration rate. The spray visualization demanded an experimental apparatus composed of a pressurized cylinder with nitrogen, a fuel tank as pressure vessel, an injection driver equipped with a peak and hold module controlled by a MoteC M84, a Phantom V7.3 high speed camera and LEDs for illumination.
2017-11-07
Technical Paper
2017-36-0236
Claudio M. Engler Pinto, Victor Algate, André Carbonara
Abstract The first production ethanol (E100) fueled capable vehicle was launched in Brazil in 1979. In the decade of 1980, most of the vehicles in Brazilian market ran either on gasohol (E22) or on ethanol. By this time, two different engine hardware had been developed: one for gasohol and one for ethanol, the latter with a higher compression ratio assuring a better fuel conversion efficiency. In this period, it was usual to have same vehicle models operating with an E100 / E22 fuel economy ratio (FE in km/l) in the range of 0.75 to 0.80. This range is greater than the E100 / E22 energy content ratio which is approximately 0.70. The customers very well perceived the higher efficiency of the ethanol-fueled vehicle when the low E100 / E22 price ratio at the pump played a major factor for this perception.
2017-11-07
Technical Paper
2017-36-0241
Renato Souza, Carlos Carvalho, Rosalvo Bertolucci
Abstract The identification of fuel blends using software strategies and the oxygen sensor are widely known for flex fuel and naturally aspirated engines in Brazil, since its first launch in 2003. It represents a cost effective alternative to identify the ethanol content in the fuel, which is being used in the combustion, with an accurate performance and reduced complexity. With the introduction of flex fuel vehicles equipped with turbocharger, especially the ones with Direct Injection (DI) technology, an ethanol sensor as an additional product has been used so far to identify the ethanol content in the fuel blend. Such engine types may be more sensitive to fuel mixture deviations, since it works with higher loads, more combustion chamber pressure and an extended temperature range in comparison with the normally aspirated applications. Due to these reasons, worst-case scenarios with high ethanol content deviation could cause damage to the engine and exhaust hardware.
2017-11-07
Technical Paper
2017-36-0357
Karsten Wittek, Frank Geiger, Jakob Andert, Mario Martins, Maurício Oliveira
Abstract The possibility to vary compression ratio offers a new degree of freedom that may enable so far not exploited benefits for the combustion process especially for highly boosted spark ignited engines. Numerous approaches to enable a variable compression ratio (VCR) have been tried and tested in the past. Nevertheless, none of these systems reached series production because of several reasons, ranging from too much complexity and moveable parts to deep modification required on existing engine architectures and manufacturing lines. Instead, the approach of a variable length conrod (VCR conrod) could be the solution for integration in almost any type of engine with minor modifications. It is then considered by several OEMs as a promising candidate for midterm series production. This paper shows, firstly, a discussion of the benefits of a variable compression ratio system.
2017-11-07
Technical Paper
2017-36-0360
Raphael Meireles Braga, Marilia Gabriela Vaz, Clarissa de Moraes Martins, Gustavo Hindi, Rudolf Huebner
Abstract The fuel injection in internal combustion engines plays a crucial role in the mixture formation, combustion process and pollutants' emission. Its correct modeling is fundamental to the prediction of an engine performance through a computational fluid dynamics simulation. In the first part of this work a tridimensional numerical simulation of a multi-hole’s injector, using ethanol as fuel, is presented. The numerical simulation results were compared to experimental data from a fuel spray injection bench test in a quiescent vessel. The break up model applied to the simulation was the combined Kelvin-Helmholtz Rayleigh-Taylor, and a sensitivity analysis of the liquid fuel penetration curve, as well on the overall spray shape was performed according to the model constants. Experimental spray images were used to aid the model tuning. The final configuration of the KH-RT model constants that showed best agreement with the measured spray was C3 equal to 0.5, B1, 7 and Cb, 0.
2017-11-07
Technical Paper
2017-36-0208
Rafael L. Sari, Diego Golke, Henrique J. Enzweiler, Kelvin F. Santos, Nina P. G. Salau, Mario E. S. Martins, Fernando M. Pereira
Abstract Hydrous ethanol is pointed out as one of the major alternative fuel for internal combustion engines, because it is environmental friendly (almost zero CO2 emission) and has excellent combustion properties. Recent studies have shown that ethanol-water fuel blends with higher water content (so-called wet ethanol) can reduce the overall costs of ethanol production. The use of wet ethanol results in lower nitrogen oxides emissions at the cost of reduced lower heating value per mass of fuel blend, which may result in less thermal efficiency. On the other hand, the increase in water content improves knock resistance. Thus, this study aims to investigate the effects of mechanical compression ratio variation on a spark ignition engine using ethanol-water fuel blends containing 4, 10, 20 and 30% v/v of water in ethanol. The research was carried out in a SI single cylinder engine, port fuel injected, 0.668 dm3 with the compression ratio modified by spacer rings.
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.
2017-11-05
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
2017-32-0054
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
2017-32-0103
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
2017-32-0101
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
2017-32-0092
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).
2017-10-08
Technical Paper
2017-01-2289
Chunze Cen, Han Wu, Chia-Fon Lee, Shuxin Hao, Fushui Liu, Yikai Li
Abstract Droplets impacting onto the heated surface is a typical phenomenon either in CI engines or in GDI SI engines, which is regarded significant for their air-fuel mixing. Meanwhile, alcohols including ethanol and butanol, has been widely studied as internal combustion engine alternative fuels due to their excellent properties. In this paper, under different component ratio conditions, the ethanol-butanol droplet impacting onto the heated aluminum surface has been studied experimentally. The falling height of the droplets were set at 5cm. A high-speed camera, set at 512×512pixels, 5000 fps and 20 μs of exposure time, was used to visualize the droplet behavior impinging onto the hot aluminum surface. The impact regimes of the binary droplet were identified. The result showed that the Leidenfrost temperature of droplets was affected by the ratio of ethanol to butanol. The higher the content of butanol in the droplet, the higher the Leidenfrost temperature.
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.
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
2017-01-2256
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
2017-01-2238
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
2017-01-2230
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
2017-01-2193
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
2017-01-2390
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
2017-01-2396
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
2017-01-2297
Thomas Dubois, Lidwine Abiad, Pauline Caine
Abstract As it is the case for Diesel engines, the Gasoline Direct Injection engines are using higher and higher injection pressures. The state of the art gasoline Direct Injection (GDI) engines are currently using injection pressures as high as 500 bar. A lot of work is also currently ongoing on Gasoline Compression Ignition (GCI) engines which use even higher injection pressures (above 1 000 bar). A high injection pressure means that a high pressure pump has to be used and so, proper lubricity has to be brought by the fuel. In the mean time the use of biofuels is increasing and several studies have shown the positive impact of ethanol on the energy consumption of gasoline engines mainly thru an octane number effect.
2017-10-08
Technical Paper
2017-01-2316
Yuhan Huang, Guang Hong, John Zhou
Abstract Ethanol direct injection (EDI) has great potential in facilitating the downsizing technologies in spark ignition engines due to its strong anti-knock ability. The fuel temperature may vary widely from non-evaporating to flash-boiling sprays in real engine conditions. In this study, a CFD spray model was developed in the ANSYS Fluent environment, which was capable to simulate the EDI spray and evaporation characteristics under non-evaporating, transition and flash-boiling conditions. The turbulence was modelled by the realizable k-ε model. The Rinzic heterogeneous nucleation model was applied to simulate the primary breakup droplet size at the nozzle exit. The secondary breakup process was modelled by the Taylor Analogy Breakup model. The evaporation process was modelled by the Convection/Diffusion Controlled Model. The droplet distortion and drag, collision and droplet-wall interaction were also included.
2017-10-08
Technical Paper
2017-01-2318
Xiaoxu Jia, Zhong Huang, Dehao Ju, Zhen Huang, Xing-cai Lu
Abstract Combustion instability often occurs inside the combustion chamber of aero engine. Fuel atomization and evaporation, one of the controlling processes of combustion rate, is an important mechanism of the combustion instability. To tackle combustion instability, it challenges a deep understanding of the underlying mechanism of fuel atomization and evaporation. In this paper, acoustic field was established to simulate the pressure oscillation. Transient spray images of ethanol and kerosene were recorded using high-speed camera. The obtained images were processed by MATLAB to extract and analyze the related data. Spatial fuel atomization characteristics was analytically examined by multi-threshold image method to analyze the effect of the high frequency acoustic field on the fuel break-up and disintegration. The results show that the half spray cone angle on the side with speaker is suppressed by the presence of the imposed acoustic field compared with the case without speaker.
Viewing 1 to 30 of 324

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