Viewing 1 to 30 of 484
Technical Paper
Rishikesh Venugopal, Neerav Abani, Ryan MacKenzie
This paper presents analytical and measured results on the effects of injection pattern design on piston thermal management in an Opposed-Piston, Two-Stroke (OP2S) diesel engine. The OP2S architecture investigated in this work comprises two opposing pistons forming an asymmetric combustion chamber with two opposing injectors mounted on the cylinder wall. This unique configuration offers opportunities to tailor the injection pattern to control the combustion heat flux and resulting temperatures on the piston surfaces while optimizing combustion simultaneously. This study utilizes three-dimensional (3D) computational fluid dynamics (CFD) with state-of-the-art spray, turbulence and combustion models that include detailed chemistry to simulate the in-cylinder combustion and the associated flame/wall interactions. In addition, the measurements comprise a real-time thermocouple system, which allows for up to 14 locations to be monitored and recorded on the intake and exhaust pistons.
Technical Paper
Yajun Liu, Wei Wang, Zhiyong Wang, Wei Wei, John Lumkes
Current gasoline-gas vapor recovery system is incomplete, for it cannot adjust the vapor-liquid ratio automatically due to the change of working temperature. To solve this problem, this paper intends to design a new system and optimize its parameters. In this research, variables control method is used for tests while linear regression is used for data processing. This new system moves proportion valve away and adds a DSP control module, a frequency conversion device, and a temperature sensor. With this research, it is clearly reviewed that the vapor-liquid ratio should remains 1.0 from 0 °C to 20 °C as its working temperature, be changed into 1.1 from 20 °C to 25 °C, be changed into 1.2 from 25 °C to 30 °C, and be changed into 1.3 when the working temperature is above 30 °C.
Technical Paper
E. G. Pariotis, D. T. Hountalas
This work is a part of an extended investigation conducted by the authors to validate and improve a newly developed quasi-dimensional combustion model. The model has been initially applied on an old technology, naturally aspirated HSDI Diesel engine and the results were satisfying as far as performance and pollutant emissions (Soot and NO) are concerned. But since obviously further and more extended validation is required, in the present study the model is applied on a new technology, heavy-duty turbocharged DI Diesel engine equipped with a high pressure PLN fuel injection system. The main feature of the model is that it describes the air-fuel mixing mechanism in a more fundamental way compared to existing multi-zone phenomenological combustion models, while being less time consuming and complicated compared to the more accurate CFD models. The finite volume method is used to solve the conservation equations of mass, energy and species concentration.
Technical Paper
Ashish Moholkar, Rizwan Khan, Jyotirmoy Barman, Sumit Arora
Increased options and flexibility in common rail direct injection provides a great opportunity for combustion optimization using fuel and air system with proper combustion chamber configuration. This paper elaborates the experimental work conducted for combustion optimization with combinations of piston bowl, intake port swirl, injector specifications and turbo charging on a 3.8 l four valve diesel engine of LDT application equipped with common rail fuel injection system and waste gate turbo charge. In meeting the target emission norms with internal engine measures, the design of the piston bowl and the nozzle configuration perform a defining role. Through simulations the best option had been carried out parametrically investigate the influence of piston bowl geometry and nozzle characteristics on the performance of the combustion system.
Technical Paper
Milene A. Luciano, Vanessa F. C. Lins
In the last decade, industries have been concerned about the processes production sustainability and with the use of alternative energies forms, in order to minimize the amount of waste generated in the process, and to suit market requirements. With this view, one alternative for automotive industry is the use of organometallic coated automotive fuel tanks. These tanks are not permeable to hydrocarbons, they do not need to be painted after stamping and are 100% recyclable. The replacement of fossil fuels with biofuels is also a way to minimize the emission of carbon dioxide in the atmosphere, reducing global warming. In this work, corrosion resistance of organometallic coated and tin coated automotive tanks, in contact with hydrated ethyl alcohol, gasoline, and diesel and soybean biodiesel was evaluated and compared, using Electrochemical Impedance Spectroscopy technique.
Technical Paper
Ossi Kaario, Anders Brink, Kalle Lehto, Karri Keskinen, Martti Larmi
New measurements have been done in order to obtain information concerning the effect of EGR and a paraffinic hydrotreated fuel for the smoke and NO emissions of a heavy-duty diesel engine. Measured smoke number and NO emissions are explained using detailed chemical kinetic calculations and CFD simulations. The local conditions in the research engine are analyzed by creating equivalence ratio - temperature (Phi-T) maps and analyzing the CFD results within these maps. The study uses different amount of EGR and two different diesel fuels; standard EN590 diesel fuel and a paraffinic hydrotreated vegetable oil (HVO). The detailed chemical kinetic calculations take into account the different EGR rates and the properties of the fuels. The residence time in the kinetical calculations is used to explain sooting combustion behavior within diesel combustion. It was observed that NO emission trends can be well captured with the Phi-T maps but the situation is more difficult with the engine smoke.
Technical Paper
P. Huyskens, S. Van Oost, P. J. Goemaere, K. Bertels, M. Pecqueur
The chicken or the egg dilemma is an often used metaphor to explain the problem where car manufacturers are not eager to produce hydrogen cars since there are no hydrogen fueling stations. Petrochemical companies on the other side, do not want to invest in hydrogen fueling stations for there are no cars to fuel. Many proposals have been made to overcome this predicament, for example starting the implementation of the hydrogen economy with early markets such as public busses that run on hydrogen, because they can use a centralized fueling infrastructure and thereby reduce initial costs. However, another way to address this stalemate is by avoiding the dependency on hydrogen fueling infrastructure. This can be achieved by using flex-fuel vehicles that can run on hydrogen as well as on gasoline and/or compressed natural gas.
Technical Paper
Harri Hillamo, Teemu Anttinen, Ulf Aronsson, Clément Chartier, Oivind Andersson, Bengt Johansson
Combination of flow field measurements, shown in this paper, give new information on the effect of engine run parameters to formation of different flow fields inside piston bowl. The measurements were carried out with particle image velocimetry (PIV) technique in optical engine. Good set of results was achieved even though the feasibility of this technique in diesel engines is sometimes questioned. Main challenge in diesel engines is background radiation from soot particles which is strong enough to conceal the PIV signal. Window staining in diesel engine is also a problem, since very high particle image quality is needed for velocity analysis. All measurements were made in an optical heavy-duty diesel engine. Optical design of engine was Bowditch type [1]. The engine was charged and equipped with exhaust gas recirculation (EGR). The exhaust gas level was monitored by oxygen concentration and the level was matched to former soot concentration measurements.
Technical Paper
Armin Wehrfritz, Ossi Kaario, Ville Vuorinen, Aki Tilli, Martti Larmi
This paper aims to study numerically the influence of the number of fuel sprays in a single-cylinder diesel engine on mixing and combustion. The CFD simulations are carried out for a heavy-duty diesel engine with an 8 hole injector in the standard configuration. The fuel spray mass-flow rate was obtained from 1D-simulations and has been adjusted according to the number of nozzle holes to keep the total injected fuel mass constant. Two cases concerning the modified mass-flow rate are studied. In the first case the injection time was decreased whereas in the second case the nozzle hole diameter was decreased. In both cases the amount of nozzle holes (i.e. fuel sprays) was increased in several steps to 18 holes. Quantitative analyses were performed for the local air-fuel ratio, homogeneity of mixture distribution, heat release rate and the resulting in-cylinder pressure.
Journal Article
Zohir Benrabah, Francis Thibault, Robert DiRaddo
A numerical simulation model for predicting the fuel hydrocarbon permeation as well as the barrier layer thickness optimization for multilayer plastic fuel tanks is presented. The diffusion model is based on Fick's laws of diffusion for a steady/unsteady state permeation regime through a multilayer polymeric wall under isothermal condition. A continuum approach based on an homogenization technique is used to model solvent diffusion through an n layer film. The hydrocarbon flux determination through the multilayer film is solved using homogenization techniques that ensure continuity of partial pressure at the polymer-polymer inter-diffusion interface. Since the pinch-off zone is known to be the major source of emission per unit area, a method has been developed to automatically detect it at the end of the extrusion blow molding process and the diffusion model is adapted to adequately evaluate the hydrocarbon permeation through this specific area.
Technical Paper
Susumu Kohketsu, Keiki Tanabe, Koji Mori
Injection rate shape control is one feature of a diesel fuel injection system that is strongly desired at this time. However, in the conventional Common Rail System (CRS), it is difficult to control the injection rate because the injection pressure is constant during the injection period, resulting in a nearly rectangular rate shape. Thus, in order to achieve injection rate control in a CRS, a Next-generation Common Rail System (NCRS) was designed and the prototype system was fabricated. With two common rails, one for low pressure fuel, and the other for high pressure fuel, the NCRS achieves injection rate shape control by controlling the fuel injector supply pressure, from the two rails. The NCRS can achieve a clear “boot” shaped injection rate, and injection rig tests confirmed that the shape could be flexibly controlled via several control parameters.
Journal Article
C.A.J. Leermakers, B. Van den Berge, C.C.M. Luijten, L.P.H. de Goey, S. Jaasma
Increasing fuel prices keep bringing attention to alternative, cheaper fuels. Liquefied Petroleum Gas (LPG) has been well known for decades as an alternative fuel for spark ignition (SI) passenger cars. More recently, aftermarket LPG systems were also introduced to Heavy Duty transport vehicles. These (port fuel) systems either vaporize the liquid fuel and then mix it with intake air, or inject fuel into the engine's intake ports. While this concept offers significant fuel cost reductions, for aftermarket certification and large-scale OEM use some concerns are present. Unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions are known to be high because of premixed charge getting trapped into crevices and possibly being blown through during valve-overlap. Apart from the higher emission levels, this also limits fuel efficiency and therefore cost savings.
Technical Paper
Derek Splitter, Reed Hanson, Sage Kokjohn, Martin Wissink, Rolf D. Reitz
Dual-fuel reactivity controlled compression ignition (RCCI) engine experiments were conducted with port fuel injection of isooctane and direct injection of n-heptane. The experiments were conducted at a nominal load of 4.75 bar IMEPg, with low isooctane equivalence ratios. Two sets of experiments explored the effects of direct injection timing with single and double injections, and multi-dimensional CFD modeling was used to explore mixture preparation and timing effects. The findings were that if fuel-liner impingement is to be avoided, double injections provide a 40% reduction in CO and HC emissions, resulting in a 1% increase in thermal efficiency. The second engine experiment showed that there is a linear relationship between reactivity (PRF number) and intake temperature. It was also found that if the premixed fuel fraction is above a certain limit, the high-temperature heat release (HTHR) can be manipulated by changing the global PRF number of the in-cylinder fuel blend.
Technical Paper
André Sperl
In the past few years the standards for pollutant emission on Diesel Engines in Brazil, especially regarding NOx and Particulate Material, have suffered drastic reductions. These reductions have been driven by international legislations and the fact that Proconve P6, equivalent to Euro IV, has been skipped in Brazil due to the unavailability of low sulfur fuel (50ppm and 10ppm), so now Proconve P7, equivalent to Euro V, would be implemented in 2012. The reductions imposed by Proconve P7(Euro V) as opposed to Proconve P5 (Euro III) the current emission legislation, determines a reduction of 60% on NOx and 80% on Particulate Matter (PM), imposing new challenges in emission control. Those emission levels can only be achieved through significant changes in the engine's hardware and the use of different after-treatment systems like the Particulate Filter (CDPF) and the Oxidation Catalyst (DOC), also using low sulfur fuel.
Technical Paper
Milene Adriane Luciano, Erick Marsalha Garcia, Maria das Merces Reis de Castro, Vanessa de Freitas Cunha Lins
For metallic tanks in contact with aqueous solution, it is always observed the presence of electrochemical corrosion. This process can cause both economic and environmental damage. In the automotive industry, fuel tanks systems have been studied in order to propose new materials to replace the plastic tanks or tanks with metallic coatings. Plastic tanks have the disadvantage of not being recyclable. In the other hand, for metallic coated tanks, tin is used as a coat material and, for this reason, the external tank side must be painted, making its productive process more expensive and generating higher amount of waste. Nowadays, organic-metallic coated tanks, in which, nickel and aluminum are the metals present, can be found. These coatings show potential application; because they do not use heavy metals in their composition and they do not require external painting, allowing a lower production cost.
Technical Paper
Yan Tan, John Kiedaisch, Steve Gravante
Fuel injector performance is critical for fuel efficiency, combustion process, emissions, start ability, acceleration and combustion noise. The injector design is a complicated process. Simulation tools are playing an important role in virtual design, which could evaluate performance and optimize the design. This paper describes how analysis is used to identify and resolve the cause of low kidney pressure when oil pressure in rail is high in a diesel injector. 1D system performance analysis tool and 3D CFD analysis tool are utilized together to identify the potential causes of the problem. The test results are compared with the simulation results to determine the root cause. 1D and CFD tools are used again to setup the design target and optimize the design. The test shows that the optimum design provided by 1D analysis and 3D analysis effectively solves the low kidney pressure problem in the fuel injector.
Technical Paper
Yan Tan, Zeguang Tao, Steve Gravante
Good performance of fuel system is critical for fuel efficiency, combustion process, emissions, start ability, acceleration and combustion noise. The fuel system design is a complicated process. Simulation tools are playing an important role in virtual design. They are used to evaluate performance, optimize the design, and provide understanding for performance or durability related problem. This paper illustrates how a 1D system simulation tool is utilized to investigate an observed failure of a high pressure hose. The simulation identifies the dominant modes in the fuel system and determines the engine speed at which the fuel system mode is excited. At various engine speeds, the simulation investigates the magnitude of pressure pulsation in the high pressure hose of the fuel system. Finally, the 1D simulation provides the design optimization approach to suppress the oil pressure pulsation and reduce the structure vibration.
Technical Paper
Raouf Mobasheri, Zhijun Peng
Effects of included spray angle with different injection strategies on combustion characteristics, performance and amount of pollutant emission have been computationally investigated in a common rail heavy-duty DI diesel engine. The CFD model was firstly validated with experimental data achieved from a Caterpillar 3401 diesel engine for a conventional part load condition at 1600 rev/min. Three different included spray angles (α = 145°, 105°, 90°) were studied in comparison with the traditional spray injection angle (α = 125°). The results show that spray targeting is very effective for controlling the in-cylinder mixture distributions especially when it accompanied with various injection strategies. It was found that 105° spray cone angle along with an optimized split pre- and post-Top Dead Center (TDC) injection strategy could significantly reduce NOx and soot emissions without much penalty of the fuel consumption, as compared to the wide spray angle.
Technical Paper
Prathan Srichai, Nuwong Chollacoop, Chinda Chareonphonphanich, Manida Tongroon, Preechar Karin
Abstract Nowadays, the diesel engine models are developed from a unit pump to a common-rail injector. With palm methyl ester (commonly known as biodiesel) with higher viscosity and density than conventional diesel being used as alternative fuel for diesel, palm methyl ester may affect the injection characteristics. Injection pressure is one of the important parameters of common rail injector. Because of its effects on the pressure between command port and control volume, which activates a needle lift during injection process. This paper presents injection characteristics of solenoid injector experimented in a Zeuch’s chamber with a focus on injection pressure frequency, injection pressure amplitude, injection pressure stable duration. Commercial diesel (with mandate of 5% biodiesel blend or B5) and palm methyl ester (B100) were used as the test fuels at various injection pressures (40, 80, 120 and 160 MPa).
Technical Paper
Avinash Dhole, Chetan Raval, Rishi Shrivastava
Abstract In commercial vehicles which generally have large capacity fuel tank, sloshing of fuel and its effect on the tank structure is very important aspect during fuel tank design. Dynamic pressures exerted by the fuel on baffles, end plates and tank shell during sloshing can lead to structural failures and fuel leakage problems. Fluid structure interaction simulation of automotive fuel tank sloshing and its correlation with physical test is demonstrated in this study. During physical sloshing test of 350 L fuel tank, cracks were observed on center baffle and spot weld failures developed on fuel tank shell. Same sloshing test was simulated for one sloshing cycle using fluid structure interaction approach in LS Dyna explicit FE solver. Water was used instead of fuel. Mesh free Smoothed Particle Hydrodynamics (SPH) method is used to represent water as it requires less computational time as compared to Eulerian or ALE method.
Technical Paper
Mengqin Shen, Sara Lonn, Bengt Johansson
Partially premixed combustion (PPC) is a promising way to achieve high efficiency and low engine-out emissions simultaneously in a heavy-duty engine. Compared to Homogeneous Charge Compression Ignition (HCCI), it can be controlled by injection events and much lower HC and CO emissions can be achieved. This work focuses on the transition from HCCI to PPC and combustion and emissions characteristics during the process are investigated. Injection strategies, EGR and boost pressure were the main parameters used to present the corresponding effect during the transition.
Technical Paper
Sumito Yokobe, Tetsuya Oda, Katsuyuki Ohsawa, Takahiro Sumi, Shuhei Sugata, Keiichiro Yabuta
The spray characteristics and inside flow of a marine diesel injector were investigated both experimentally and numerically. From the experiments, we observed that the penetration of the sprays in the early injection stage gradually increases. This phenomenon differs significantly from that of the small automobile diesel injector, in which penetration increases linearly with time. Using the momentum method to obtain injection rate measurements, we observed an injection rate spike at each injection event just after the injection began. The observed spray results show that the small portion of fuel remaining inside the nozzle from the previous injection event is ejected first, and then the main volume of fuel is ejected. Both fuels accumulate as spray droplets and gradually accelerate after the early injection stage. Numerical simulations of the injector's inside flow show that the fuel injection rate becomes saturated in needle lifts larger than 0.3 mm.
Technical Paper
Hideaki Osada, Noboru Uchida, Yoshio Zama
Impingement of a spray flame on the periphery of the piston cavity strongly affects heat loss to the wall. The heat release rate history is also closely correlated with the indicated thermal efficiency. For further thermal efficiency improvement, it is thus necessary to understand such phenomena in state of the art diesel engines, by observation of the actual behavior of an impinging spray flame and measurement of the local temperature and flow velocity. A top-view optically accessible engine system, for which flame impingement to the cavity wall can be observed from the top (vertically), was equipped with a high speed digital camera for direct observation. Once the flame impinged on the wall, flame tip temperature decreased roughly 100K, compared to the temperature before impingement.
Technical Paper
Takahito Niwa, Takashi Eguchi, Koichi Yamada, Satoshi Bunne, Toshihiko Omori, Takafumi Kato
With the diesel emissions and fuel consumption regulations and laws being tightened up, Common Rail System (CRS), capable of accurate and high-pressure diesel fuel injection, has become very popular in the world, and this CRS market is expected to continue to grow in the future. As use of the CRS becomes widespread, CRS is supposed to be used in a wide variety of environment, e.g. bad fuel (for example, much dust [1] and/or water), which increases concerns of CRS reliability. In an attempt to cope with such bad fuel properties, CRS and Fuel collected from the market was investigated. And based on this result, a new test method was worked out to simulate fuel stresses in the market. This test method verified the improved design of CRS with enhanced fuel robustness. This paper describes the new test method and the fuel robustness-enhancing effect of CRS based on the test method.
Technical Paper
Beat von Rotz, Kai Herrmann, Konstantinos Boulouchos
Fuel spray propagation and its morphology are important aspects for the in-cylinder mixture preparation in Diesel engines. Since there is still a lack of suitable measurements with regard to large 2-stroke marine Diesel engines combustion systems, a comprehensive data set of spray characteristics has been investigated using a test facility reflecting the specific features of such combustion systems. The spray penetration, area and cone angle were analysed for a variation of gas density (including the behaviour at evaporation and non-evaporating conditions), injection pressure and nozzle diameter. Moreover, spray and swirl flow interaction as well as fuel quality influences have been studied. To analyse the impacts and effects of each measured parameter, an empirical correlation for the spray penetration has been derived and discussed for all measurements presented.
Journal Article
Gordon McTaggart-Cowan, Ken Mann, Jian Huang, Ashish Singh, Bronson Patychuk, Zheng Xiong Zheng, Sandeep Munshi
Abstract Retaining the diesel combustion process but burning primarily natural gas offers diesel-like efficiencies from a natural-gas fuelled heavy-duty engine. This combustion event is limited by the injection pressure of the fuel, as this dictates the rate of mixing and hence of combustion. Typical late-cycle direct injection applications are limited to approximately 300 bar fuel pressure. The current work reports on tests for the first time at natural gas injection pressures up to 600 bar. The results show that significant efficiency and particulate matter reductions can be achieved at high loads, especially at higher speeds where the combustion is injection rate limited at conventional pressures. Increases in combustion noise and harshness are a drawback of higher pressures, but these can be mitigated by reducing the diameter of the nozzle gas holes to control the fuel injection rate.
Technical Paper
Rafael Hilario Fonseca Mazzorana, Olício da Silva Junior, Roberson Assis de Oliveira
Abstract The proper technology selection, depending on the application environment, will be discussed and exemplified in this paper through the analysis of the fuel level sensor technology selection applied to the Latin America environment. Commercial vehicles have a very particular requirement when it comes to fuel tanks configuration, depending on usage (autonomy), road conditions, weight distribution and application. The most common layout is the dual tank configuration where two tanks are connected to each other by means of communication vessels. After the selection of the fuel tank layout, the challenge is to correctly select the level sensor system, which provides useful information to the vehicle driver. If this measurement is not correctly performed, a significant logistic issue is raised, as usually, a commercial vehicle with full load carries up to 1200 liters of diesel (it will depend on the desired range).
Technical Paper
Sauhard Singh, Reji Mathai, A. K. Sehgal, R. Suresh, B. P. Das, Nishant Tyagi, Jaywant Mohite, N. B. Chougule
Abstract Depletion of fossil fuel reserves, the unsteadiness of their prices and the increasingly stricter exhaust emission legislation put forward attention of world towards use of alternate fuels. The ever increasing demand for ecologically friendly vehicles can be met by use of clean fuels like Compressed Natural Gas (CNG) and Hydrogen (H2). Lower carbon to hydrogen ratio of CNG makes it a cleaner fuel, due to this CNG is gaining popularity as an internal combustion (IC) engine fuel in transport sector. Hydrogen fuel for IC engines is also being considered as a future fuel due to its simple carbon less structure. However, several obstacles have to be overcome before widespread utilization of hydrogen as an IC engine fuel can occur in the transport sector. The 18 percent hydrogen enriched CNG fuel referred to as HCNG has the potential to lower emissions and could be considered a first step towards promotion of a Hydrogen economy.
Technical Paper
Umashankar Mohan Chandra Joshi, Manan Jyotin Trivedi, Ziliang Zheng, Peter Schihl, Naeim A. Henein
All previous correlations of the ignition delay (ID) period in diesel combustion show a positive activation energy, which means that shorter ID periods are achieved at higher charge temperatures. This is not the case in the autoignition of most homogeneous hydrocarbons-air mixtures where they experience the NTC (Negative Temperature Coefficient ) regime in the intermediate temperature range, from about 800 K to 1000 K). Here, the autoignition reactions slow down and longer ID periods are experienced at higher temperatures. Accordingly the global activation energy for the autoignition reactions of homogeneous mixtures should vary from positive to negative values.
Technical Paper
Dhruv Gupta, Vasu Kumar, Soumya Roy, Naveen Kumar
Abstract The danger posed by climate change and the striving for securities of energy supply are issues high on the political agenda these days. Governments are putting strategic plans in motion to decrease primary energy use, take carbon out of fuels and facilitate modal shifts. Man's energy requirements are touching astronomical heights. The natural resources of the Earth can no longer cope with it as their rate of consumption far outruns their rate of regeneration. The automotive sector is without a doubt a chief contributor to this mayhem as fossil fuel resources are fast depleting. The harmful emissions from vehicles using these fuels are destroying our forests and contaminating our water bodies and even the air that we breathe. The need of the hour is to look not only for new alternative energy resources but also clean energy resources. Hydrogen is expected to be one of the most important fuels in the near future to meet the stringent emission norms.
Viewing 1 to 30 of 484


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