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Viewing 1 to 30 of 16773
2017-10-24
Journal Article
2017-01-9377
Silambarasan Rajendran, Senthil Ramalingam
Abstract Biodiesel as an alternative diesel fuel prepared from vegetable oils or animal fats has attracted more and more attention because of its renewable and environmental friendly nature. Many recent studies shows that 20% proportion of biodiesel-diesel blend (B20) can substantially reduce the hydrocarbon (HC), carbon monoxide (CO) and smoke emissions. However, there is a slight increase in NOx emission for B20 than that of diesel and it was a barrier to market expansion. The addition of antioxidant additives was the most effective method to mitigate the NOx emission. Hence, in this paper experimental investigation has been carried out to mitigate the NOx emission in Annona biodiesel (A20) operated diesel by addition of antioxidant additives. The antioxidant additives such as p-phenylenediamine, A-tocopherol acetate and L-ascorbic acid were used in the present investigation. In recent years Annona biodiesel has been considered as potential novel renewable energy source in India.
2017-10-08
Technical Paper
2017-01-2325
Midhat Talibi, Paul Hellier, Nicos Ladommatos
The conversion of lignocellulosic biomass to liquid fuels presents an alternative to the current production of renewable fuels for IC engines from food crops. However, realising the potential for reductions in net CO2 emissions through the utilisation of, for example, waste biomass for sustainable fuel production requires that energy and resource inputs into such processes be minimised. This work therefore investigates the combustion and emission characteristics of five intermediate platform molecules potentially derived from lignocellulosic biomass: gamma-valerolactone (GVL), methyl valerate, furfuryl alcohol, furfural and 2-methyltetrahydrofuran (MTHF). The study was conducted on a naturally aspirated, water cooled, single cylinder spark-ignition engine. Each of the platform molecules were blended with reference fossil gasoline at 20 % wt/wt.
2017-10-08
Technical Paper
2017-01-2328
Yuanxu Li, Karthik Nithyanandan, Han Wu, Chia-Fon Lee, Zhi Ning
Bio-butanol has been widely investigated as a promising alternative fuel. However, the main issues preventing the industrial-scale production of butanol is its relatively low production efficiency and high cost of production. Acetone-butanol-ethanol (ABE), the intermediate product in the ABE fermentation process for producing bio-butanol, has attracted a lot of interest as an alternative fuel because it not only preserves the advantages of oxygenated fuels, but also lowers the cost of fuel recovery for individual component during fermentation. If ABE could be directly used for clean combustion, the separation costs would be eliminated which save an enormous amount of time and money in the production chain of bio-butanol.
2017-10-08
Technical Paper
2017-01-2291
Sandro Gail, Takashi Nomura, Hitoshi Hayashi, Yuichiro Miura, Katsumi Yoshida, Vinod Natarajan
In emerging markets, Port Fuel Injection (PFI) technology retains a higher market share than Gasoline Direct Injection (GDI) technology. In these markets fuel quality remains a concern even despite an overall improvement in quality. Typical PFI engines are sensitive to fuel quality regardless of brand, engine architecture, or cylinder configuration. One of the well-known impacts of fuel quality on PFI engines is the formation of Intake Valve Deposits (IVD). These deposits steadily accumulate over time and can lead to a deterioration of engine performance. IVD formation mechanisms have been characterized in previous studies. However, no test is available on a state-of-the-art engine to study the impact of fuel components on IVD formation. Therefore, a proprietary engine test was developed to test several chemistries. Sixteen fuel blends were tested. The deposit formation mechanism has been studied and analysed.
2017-10-08
Technical Paper
2017-01-2247
Wenbin Zhang, Haichun ding, Shijin Shuai, Bin Zheng, Alex Cantlay, Vinod Natarajan, Zhang Song ZHAN, Yunping Pu
Gasoline direct injection (GDI) engines have been developed rapidly in recent years, driven by stringent legislation requirements on vehicle fuel efficiency and emissions. However it faces the great challenge of particulate emissions especially when the injector deposits are formed. The gasoline fuel in Chinese market basically contains no detergents but high levels of aromatics and olefin components, which makes it easy to accumulate the injector deposits affecting the engine performance and emissions. To solve this issue, the gasoline with detergents is a viable solution. In this study, a 1.5L turbocharged GDI engine developed by a Chinese manufacturer was selected to investigate the injector deposit formation and its impact on engine performance and emissions. The test was then repeated by using gasoline with detergents provided by Shell to research the effect of detergents on the mitigation of injector deposits.
2017-10-08
Technical Paper
2017-01-2323
Lei Li, Kai Sun, Jianyu Duan
Butanol is a promising alcohol fuel. Previous studies in flames and diesel engines showed different trends in sooting tendencies of the butanol isomers (n-butanol, iso-butanol, sec-butanol and tert-butanol). However, the impact of butanol isomers on the particulate emissions of GDI (Gasoline Direct Injection) engines has not been reported. This work examined the combustion performance and particle number emissions of a GDI engine fueled with gasoline/butanol blends at steady state modes. Each isomer was tested at the blend ratio 10% to 50% by volume. Spark timings for all the fuels were set to obtain the maximum break torque, i.e. the MBT spark timings. Results showed that the particle number concentration could be reduced significantly with the increasing butanol content for all the isomers.
2017-10-08
Technical Paper
2017-01-2259
Tianpu Dong, Fujun Zhang, Hongli Gao, Sufei Wang, Yidong Fei
The diesel low temperature combustion(LTC) can keep high efficiency and produce low emission. It has been widely studied at home and abroad in recent years. The combustion control parameters such as injection pressure, injection timing, intake oxygen concentration, intake pressure, intake temperature and so on, have an important influence on the combustion and emission of diesel LTC. In order to realize different combustion modes and combustion mode switch of diesel engine, it is necessary to accurately control the injection parameters and intake parameters of diesel engine. In this work, the effect of intake oxygen concentration, intake pressure and intake temperature on the combustion and emission characteristics of diesel LTC were analyzed by experimental study. Combustion performance and emission characteristics such as in-cylinder pressure, temperature, heat release rate, NOx and soot emission are presented and discussed.
2017-10-08
Technical Paper
2017-01-2363
Murugesa Pandian M, Anand Krishnasamy
The major limitations in a conventional high temperature diesel combustion are higher oxides of nitrogen (NOx) and particular matter (PM) emissions and a trade-off between them. Advanced low temperature combustion (LTC) strategies are proposed to simultaneously reduce NOx and PM emissions to near zero levels along with higher thermal efficiencies. Various LTC strategies including Premixed Charge Compression Ignition (PCCI), Homogenous Charge Compression Ignition (HCCI), Reactivity Controlled Compression Ignition (RCCI), Stratified Charge Compression Ignition (SCCI) and High Efficiency Clean Combustion (HECC) are proposed so far to achieve near zero NOx and PM emissions along with higher thermal efficiencies. Each of these LTC strategies have their own advantages and limitations interms of precise ignition control, achievable load range and higher unburned emissions.
2017-10-08
Technical Paper
2017-01-2364
Jiaqiang Li, Chao He, Jianwei Tan, Zihang Peng, Zidi Li, Wei Chen, Shijie wang
Urea selective catalytic reduction is the most promising technique to reduce NOx emissions from heavy duty diesel engines. 32.5wt% aqueous urea solution is widely used as ammonia storage species for the urea selective catalytic reduction process. The thermolysis and hydrolysis of urea produces reducing agent ammonia and provides to catalysts to reduce NOx emissions to nitrogen and water. However, the application of urea SCR technology has many challenges at low temperature conditions, such as deposits formation in the exhaust pipe, lack deNOx performance at low temperature and freezing below -12℃. For preventing deposits formation, the aqueous urea solution is difficult to be injected into the exhaust gas stream at temperature below 200℃. The aqueous urea solution used as reducing agent precursor is the main obstacle for achieving high deNOx performances at low temperature conditions.
2017-10-08
Technical Paper
2017-01-2365
Murugesa Pandian M, Anand Krishnasamy
Reactivity controlled compression ignition (RCCI) is one of the most promising low temperature combustion (LTC) strategies to achieve higher thermal efficiencies along with ultra low oxides of nitrogen (NOx) and particulate matter emissions. Small single cylinder diesel engines of air-cooled type are finding increasing applications in the agriculture pump-set and small utility power generation owing to their lower cost and fuel economy advantages. In the present work, a small single cylinder diesel engine is initially operated under conventional combustion mode at rated speed, varying load conditions to establish the base line reference data. Then, the engine is modified to operate under RCCI combustion mode with a newly designed cylinder head to accommodate a high pressure, fully flexible electronically controlled direct diesel fuel injection system, a low pressure gasoline port fuel injection system and an intake air pre heater.
2017-10-08
Technical Paper
2017-01-2367
Ganesan Mahadevan PhD, Sendilvelan Subramanian
Control of harmful emissions during cold start of the engine has become a challenging task over the years due to the ever increasing stringent emission norms. Positioning the catalytic converter closer to the exhaust manifold is an efficient way of achieving rapid light-off temperature. On the other hand, the resulting higher thermal loading under high-load engine operation may substantially cause thermal degradation and accelerate catalyst ageing. The objective of the present work is to reduce the light-off time of the catalyst and at the same time reduce the thermal degradation and ageing of the catalyst to the minimum possible extent by adopting an approach with Dynamic Catalytic Converter System (DCCS). The emission tests were conducted at the cold start of a 4 cylinder spark ignition engine with DCCS at different positions of the catalyst at no load conditions.
2017-10-08
Technical Paper
2017-01-2368
Wenji Song, Weiyong Tang, Bob Chen, Jiapeng zhang
The 4JB1 diesel engine originated from Isuzu has large share in the China light duty truck market. However, the tightened NOx emission target enforced by NS-V legislation compared with NS-IV regulatory standard is very challenging for this engine platform which originally adopted the DOC+POC catalyst layout. Furthermore, combustion characterization of this type engine leads to high soluble organic fration (SOF) content in engine out particulates, which requires the catalysts in the exhaust after-treatment system (ATS) to deliver high SOF conversion efficiency in order to meet the regulation limit for particulate matters (PM). In this paper, an innovative DOC+V-SCR exhaust catalyst layout with DOC+V-SCR is introduced. The front DOC is specially formulated with optimized PGM (Platinum Group Metal) loading which ensures effective SOF oxidation while keeping sulfuric acid and sulfate generation minimal.
2017-10-08
Technical Paper
2017-01-2381
Kristian Hentelä, Ossi Kaario, Vikram Garaniya, Laurie Goldsworthy, Martti Larmi
In the present study, a new approach for modelling emissions of coke particles or cenospheres from large diesel engines using HFO (Heavy fuel oil) was studied. The used model is based on a multicomponent droplet mass transfer and properties model that uses a continuous thermodynamics approach to model the complex composition of the HFO fuel and the resulting evaporation behavior of the fuel droplets. Cenospheres are modelled as the residue left in the fuel droplets towards the end of the simulation. The mass-transfer and fuel properties models were implemented into a cylinder section model based on the Wärtsilä W20 engine in the CFD-code Star CD v.4.24. Different submodels and corresponding parameters were tuned to match experimental data of cylinder pressures available from Wärtsilä for the studied cases. The results obtained from the present model were compared to experimental results found in the literature.
2017-10-08
Technical Paper
2017-01-2405
Christophe Chaillou, Alexandre Bouet, Arnaud Frobert, Florence Duffour
Fuels from crude oil are the main energy vectors used in the transport sector but these fuels associated to CI engines are nowadays often criticized. Nevertheless, engine and fuel co-research is one of the main leverage to reduce both CO2 footprint and criteria pollutants. CI engines, with gasoline-like fuels, are a promising way for NOx and particulates emission abatement while keeping lower CO2 emission. To introduce a new fuel/engine technology, investigations of pollutants are mandatory. Previous work [1] already studied the behavior of low RON gasoline soot generated with a CI engine. The aim of this paper is to assess the impact of such fuel/engine technology on the HC emissions and on the DOC behavior. HC speciation is performed upstream and downstream DOC. Warm-up and efficiency are also tested for different operating conditions. Then, exothermal capacities are considered to ensure high level of temperature for DPF regeneration.
2017-10-08
Technical Paper
2017-01-2386
Naoki Ohya, Kohei Hiyama, Kotaro Tanaka, Mitsuru Konno, Atsuko Tomita, Takeshi Miki, Yutaka Tai
Diesel engines have better fuel economy over comparable gasoline engines and useful for the reduction of CO2 emissions. However, to meet stringent emission standards, the technology for reducing NOx and particulate matter (PM) in diesel engine exhaust needs to be improved. A conventional selective catalytic reduction (SCR) system consists of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and an urea-SCR catalyst. Recently, more stringent regulations have led to the development of SCR systems with a larger volume and increased the cost of such systems. In order to solve these problems, an SCR catalyst coated on DPF (SCR/DPF) is proposed. An SCR/DPF system has a lower volume and cost compared with the conventional SCR system. The SCR/DPF catalyst has two functions: one is combustion of PM and the other is reduction of NOx emissions.
2017-10-08
Technical Paper
2017-01-2255
Raul Payri, Jaime Gimeno, Santiago cardona, Sridhar Ayyapureddi
In this article, a prototype multi-hole diesel injector from a high-pressure common rail system is used in a high-pressure and high-temperature test rig capable of reaching 1100 Kelvin and 150 bars under different oxygen concentrations. A novel optical set-up capable of visualizing the soot cloud evolution from 30 to 85 millimeters from the nozzle exit with the high-speed color diffused back illumination technique is used thanks to the insertion of a high-pressure window in the injector holder opposite to the frontal window of the vessel. Experimental results show the reduction of soot formation with an increase in injection pressure, a reduction in chamber temperature, a reduction in oxygen concentration or a reduction in chamber density.
2017-10-08
Technical Paper
2017-01-2424
Shemin zhang, Huaping Li, Tao Chen, Nan Jiang, Xinzhen Tan, Limei Deng, Qingsong Xia, Paul Kapus, Mingtang Ma, Wei Li, Junqiang Zhang, Qingjun Ma, Yong Xia
In recent years, more attentions have been paid to stringent legislation on fuel and emissions. Turbocharged downsizing DI engine is playing an increasing vital role in OEM’s powertrain strategies. Dongfeng Motor (DFM) has developed a new type of 1.0-liter 3 cylinder TGDI gasoline engine to meet the requirements of China 4th stage fuel consumption regulations and the China 6 emission standards. In this paper, the concepts of DFM 3-cylinder 1.0TGDI gasoline engine are explored to meet the powerful performance (torque 190Nm/1500-4500rpm and power 95kW/5500rpm), excellent part-load BSFC and NVH targets to ensure the drivers could enjoy the powerful output in quiet and comfortable environment without concerning about the fuel cost and pollution. The combustion system with side-mounted 6-hole direct injector and 200bar injection pressure has been optimized by CFD simulation and transparent engine investigation.
2017-10-08
Technical Paper
2017-01-2375
Akihiro Niwa, Shogo Sakatani, Eriko Matsumura, Takaaki Kitamura
Diesel engine has low carbon emissions and high fuel efficiency. However, diesel engine needs to reduce both Nitrogen Oxide (NOx) and Particulate matters (PM). To meet the demand of strict exhaust gas regulation, after-treatment device is required. Therefore, urea SCR (Selective Catalytic Reduction) system is used to clean NOx in diesel engine exhaust gas. In urea SCR system, it is necessary to inject the urea water solution upstream the SCR catalyst. And, it can reduce NOx applying the generated ammonia (NH3) by urea thermolysis and isocyanic acid (HNCO) hydrolysis. In this study, it focused on urea SCR system. The spray behavior injected in tail-pipe can be divided into the regime of a free spray, an impingement spray, an evaporation of liquid film and a separation droplets, and an urea water solution dispersion. Also, in each region, after evaporation of H2O in urea water solution completely, NH3 is generated by urea thermolysis and HNCO hydrolysis.
2017-10-08
Technical Paper
2017-01-2361
David R. Lancaster
The auto industry today is a global industry that must conform to local emissions and fuel consumption regulation in virtually all markets. These regulations apply different methodologies to different test cycles. This variation in methodologies and test cycles makes direct comparison of standards difficult. This paper compares the NEDC, WLTC and US EPA driving cycles by examining the tractive energy requirements of vehicles from the 2017 US fleet on each of the cycles. In addition, the mass and footprint data from those vehicles are used to compute the CO2 standards for each vehicle under European, US and Chinese standards.
2017-10-08
Technical Paper
2017-01-2366
Wenzheng Xia, Yi Zheng, Xiaokun He, Dongxia Yang, Huifang Shao, Joesph Remias, Joseph Roos, Yinhui Wang
Because of the increased use of gasoline direct engine (GDI) in automobile industry, there is a significant need to control particulates from GDI engines based on emission regulations. One potential technical approach is the utilization of a gasoline particulate filter (GPF). The successful adoption of this emission control technology needs to take many aspects into consideration and requires a system approach for optimization. This study conducted research to investigate the impact of vehicle driving cycles, fuel properties, catalyst coating on the performance of GPF. It was found that driving cycle has significant impact on particulate emission. Fuel quality still plays a role in particulate emissions, and can affect the GPF performance. Catalyzed GPF is preferred for soot regeneration, especially for the case that the vehicle operation is dominated by congested city driving condition, i.e. low operating temperatures. The details of the study are presented in the paper.
2017-10-08
Technical Paper
2017-01-2267
Erik Svensson, Lianhao Yin, Per Tunestal, Martin Tuner
The concept of Partially Premixed Combustion (PPC) in engines has shown to achieve very high gross indicated efficiencies, but at the expense of gas exchange efficiencies. Most of the experimental research on PPC has been conducted on compression ignition engines designed to operate on diesel fuel and relatively high exhaust temperatures. The PPC concept on the other hand relies on dilution with high exhaust gas recirculation (EGR) rates to slow down the combustion which results in low exhaust temperatures, but also high mass flows over cylinder, valves, ports and manifolds. A careful design of the gas exchange system, EGR and charge air coolers is therefore of utter importance. Experiments were performed on a heavy-duty, compression ignition engine using a fuel consisting of 80 percent 89 RON gasoline and 20 percent n-heptane. A wide range of engine speeds and loads were run using a long route EGR system.
2017-10-08
Technical Paper
2017-01-2288
Tianyuan Zhou, Changsheng Yao, Fuyuan Yang
Low temperature combustion (LTC) is an advanced combustion mode, which can achieve low emissions of NOx and PM simultaneously, and keep relatively high thermal efficiency at the same time. However, one of the major challenges for LTC is the cold condition. In cold conditions, stable compression ignition is hard to realize, while thermal efficiency and emissions deteriorate, especially for gasoline or fuel with high octane number. This study presents using pressure sensor glow plugs (PSG) to realize Glow plug assisted compression ignition (GA-CI) at cold conditions. Further, a glow plug control unit (GPCU) is developed, a closed-loop power feedback control algorithm is introduced based on GPCU. In the experiment, engine coolant temperature is swept. Experimental results show that GA-CI has earlier combustion phases, larger combustion duration and higher in-cylinder pressure. And misfire is avoided, cycle-to-cycle variations are greatly reduced.
2017-10-08
Technical Paper
2017-01-2285
Eric Randolph, Raphael Gukelberger, Terrence Alger, Thomas Briggs, Christopher Chadwell, Antonio Bosquez Jr
The primary focus of this investigation was to determine the hydrogen reformation, efficiency and knock mitigation benefits of methanol-fueled Dedicated EGR operation, when compared to other EGR types. A 2.0 L turbocharged port fuel injected engine was operated with internal EGR, low-pressure loop (LPL) EGR and Dedicated EGR (D-EGR®) configurations. The internal, LPL-EGR, and D-EGR configurations were operated on neat methanol to display the relative benefit of D-EGR over other EGR types, while the DEGR configuration was also tested on high octane gasoline to highlight the differences and benefits to D-EGR operation of methanol compared to gasoline. Additional sub-tasks of the work were to investigate combustion stability, ignition energy requirements and burn rates. It was found that methanol did not increase its H2 yield rate for a given D-EGR cylinder equivalence ratio, even though the H:C ratio of methanol is over twice typical gasoline.
2017-10-08
Technical Paper
2017-01-2182
Xikai Liu, Xingyu Liang, Yonge Wu
According to the study of the soot emission in marine diesel, ,a new reduced mechanism for n-heptane was constructed to describe the combustion process in diesel engine by using sensitivity analysis.Furthermore,verifying the ignition delay time,the laminar flame speed,the flame propagation distance and species profiles in combustion process by using Chemkin Pro in different pressure(13.5atm and 42 atm),initial temperatures and equivalence ratio(0.5 and 1.0).Then,compare the simulated result with the experiment data and the simulated result by using LLNL(lawrence livermore national laboratory)detail mechanism and SKLE(state key laboratory of engine)mechanism.It is demonstrated that the reduced mechanism can not describe the ignition delay time in low temperature.And then,the reduced mechanism was adjusted and optimized to make it more close to the experiment data,and the reduced mechanism were able to predict ignition delay time,laminar flame speed,flame propagation distance and species profiles.The final reduced n-heptane mechanism are more compact compare with the current detailed mechanisms in literature.Thus,this reduced n-heptane mechanism can reduce the pressure of calculation and save the calculation time.
2017-10-08
Technical Paper
2017-01-2190
Alessandro D'Adamo, Marco Del Pecchia, Sebastiano Breda, Fabio Berni, Stefano Fontanesi, Jens Prager
CFD simulations of reacting flows are fundamental investigation tools used to predict combustion behaviour and pollutants formation in modern spark-ignition internal combustion engines. Most of the flamelet-based combustion models adopted in current simulations use the fuel/air/residual laminar flame speed as a background to predict the turbulent flame speed. This in turn is a fundamental requirement to model the effective burn rate. The consolidated approach in engine combustion simulations relies on the adoption of empirical correlations for laminar flame speed, which are derived from fitting activity of combustion experiments. However, these last are conducted at largely different pressure and temperature ranges from those encountered in engines: for this reason, correlation extrapolation at engine conditions is inevitably accepted and relevant differences between proposed correlations emerge even for the same fuel and conditions.
2017-10-08
Technical Paper
2017-01-2200
Peter Priesching, Mijo Tvrdojevic, Ferry Tap PhD, Casper Meijer
Turbulent combustion modeling in a RANS or LES context imposes the challenge of closing the chemical reaction rate on the sub-grid level. Many turbulent combustion models exist in literature. Such turbulent models have as their two main ingredients sources from chemical reactions and turbulence-chemistry interaction. The various combustion models then differ mainly by how the chemistry is calculated (level of detail, canonical flame model) and on the other hand how turbulence is assumed to affect the reaction rate on the sub-grid level (turbulence-chemistry interaction - TCI). In this work, an advanced combustion model based on tabulated chemistry is applied for 3D CFD modeling of Diesel engine cases. The combustion model is based on the Flamelet Generated Manifold (FGM) chemistry reduction technique. The underlying chemistry tabulation process uses auto-ignition trajectories of homogeneous fuel/air mixtures, which are computed with detailed chemical reaction mechanisms.
2017-10-08
Technical Paper
2017-01-2232
Ho Teng
Atkinson cycle realized with a late intake valve closing (LIVC) and Miller cycle achieved with an early intake valve closing (EIVC) have been recognized as effective approaches for improving the gasoline engine fuel economy. In both Atkinson and Miller cycles, the engine can be designed with a higher geometric compression ratio for increasing the expansion work and the effective compression ratio is governed by the intake valve close (IVC) timing for the knock control. Duration of the intake event and IVC timing affect not only the pumping loss during the gas exchange, but also have strong influences on the friction torques of the intake cams and the turbulence intensities for the in-cylinder charge motion. The latter governs duration of combustion and EGR tolerance, both of which have impacts on the engine thermal efficiency.
2017-10-08
Technical Paper
2017-01-2249
Chen Wang, Tianyou Wang, Kai Sun, Zhen Lu, Yong Gui
Clean combustion is critical for marine engines to meet the Tier III emission regulation. In this paper, the effects of EGR and injection strategies (including injection pressure, injection timing as well as multiple injection technology) on the performance and emissions of a 2-stroke, low speed marine diesel engine were investigated by using computational fluid dynamics (CFD) simulations to reach the IMO Tier III NOx emissions target and reduce the fuel consumption rate. Due to the large length scale of the marine engine, RANS simulation was performed in combination with the CTC-SHELL combustion model. Based on the simulation model, the variation of the cylinder pressure curve, the average temperature in the cylinder, the combustion heat release rule and the emission characteristics were studied.
2017-10-08
Technical Paper
2017-01-2254
Sirui Huang, Changpu Zhao, Yayong Zhu
In order to improve the combustion and emissions for high-speed marine diesel engines, numerical investigations on effects of different combustion chamber structures combined with intake air humidification have to be conducted in this paper. The study uses AVL Fire code to establish three-dimensional combustion model and simulate the in-cylinder flow, air-fuel mixing and combustion process with the flow dynamics metrics such as swirl number and uniformity index, analyze the interactional effects of combustion chamber structures and intake air humidification against the experimental data for a part load operation at 1350 r/min, find the optimized way to improve engine performance as well as decrease the NOx and soot emissions. The novelty is that this study is to combine different air humidifying rates with different combustion chamber structures including the re-entrant chamber, the straight chamber and the open chamber.
2017-10-08
Technical Paper
2017-01-2263
S. vedharaj, R vallinayagam, Yanzhao An, Mohammad Izadi Najafabadi, Bart Somers, Junseok Chang, Bengt Johansson
Naphtha boils in the gasoline range of 40°C to 75°C with a RON of 65, showing increased resistance to auto-ignition. It is not possible to use naphtha as a drop in fuel for CI engine and therefore, it is ideal to investigate premixed combustion of naphtha. Previous studies reports the use of naphtha in CI engine under partially premixed combustion (PPC) mode, wherein the fuel injection timing and intake air temperature controls combustion. In this study, we investigate the combustion visualization and stratification of surrogate fuel in PPC mode. The composition of naphtha surrogate is 2-methyl butane (0.21% mol), 2-methyl hexane (0.07% mol), n-pentane (0.6% mol), n-heptane (0.07% mol) and toluene (0.05% mol). Investigation of surrogate fuel in engine expands on the previous studies on surrogate fuel formation for naphtha. Based on the experimental outcome, start of injection (SOI) was found to be inversely correlated with combustion phasing during early injection timings.
Viewing 1 to 30 of 16773