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Viewing 1 to 30 of 4869
2017-10-08
Technical Paper
2017-01-2197
Vignesh Pandian Muthuramalingam, Anders Karlsson
Owing to increased interest in blended fuels for automotive applications, a great deal of understanding is sought for the behavior of multicomponent fuel sprays. This sets a new requirement on spray model since the volatility of the fuel components in a blend can vary substantially. It calls for careful solution to implement the differential evaporation process concerning thermodynamic equilibrium while maintaining a robust solution. This work presents the Volvo Stochastic Blob and Bubble (VSB2) spray model for multicomponent fuels. A direct numerical method is used to calculate the evaporation of multicomponent fuel droplets. The multicomponent fuel model is implemented into OpenFoam CFD code and the case simulated is a constant volume combustion vessel. The CFD code is used to calculate liquid penetration length for surrogate diesel (n-dodecane)-gasoline (iso-octane) blend and the result is compared with experimental data.
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
2017-01-2198
Zhihong Li, Guoxiu Li, Lan Wang, Hongmeng Li, Jie Wang, Haizhou Guo, Shuangyi He
The electromagnetic valve driving mechanism is the significant equipment, which plays a vital role in the unit pump injection system; therefore, the performance of the electromagnetic valve directly influences the function of the control system. Based on the operation conditions of the unit pump injection system, a steady electromagnetic valve model was modified to study the influence factors of electromagnetic force and the best combination to get the maximum electromagnetic force. The validation model was verified by experiment. The effects of some crucial parameters upon the electromagnetic force were investigated in the present paper, (including working airspace, magnetic pole’s cross-sectional area, coil position, coil turn, the armature thickness). The result shows that the electromagnetic force of the solenoid valve enhanced with the increasing driving current and reduced with the decreasing of working condition.
2017-10-03 ...
  • October 3-4, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
As diesel engines become more popular, a fundamental knowledge of diesel technology is critical for anyone involved in the diesel engine support industry. This course will explain the fundamental technology of diesel engines starting with a short but thorough introduction of the diesel combustion cycle, and continue with aspects of engine design, emission control design, and more. An overview of developing technologies for the future with a comprehensive section on exhaust aftertreatment is also included. The text, Diesel Emissions and Their Control, authored by Magdi Khair and W. Addy Majewski is included with the seminar.
2017-09-04
Technical Paper
2017-24-0083
Hassan Khatamnejad, Shahram Khalilarya, Samad Jafarmadar, Mostafa Mirsalim, Mufaddel Dahodwala
Abstract RCCI strategy gained popularity in automotive applications due to lower fuel consumption, less emissions formation and higher engine performance in compared with other diesel combustion strategies. This study presents results of an experimental and numerical investigation on RCCI combustion using natural gas as a low reactivity premixed fuel with advanced injection of diesel fuel as a high reactivity fuel in a CI engine. An advanced three dimensional CFD simulation coupled with chemical kinetic developed to examine the effects of diesel injection timing, diesel/natural gas ratio and diesel fuel included spray angle on combustion and emissions formation in various engine loads and speeds, in a heavy duty diesel engine.
2017-09-04
Technical Paper
2017-24-0102
N Balasubramanian, Jayabalan Sethuraman, Titus Iwaszkiewicz
In this paper, two different concepts of fuel-pumping methods using solenoid, for gasoline injection in engines, are discussed. The fuel pump is integrated within injector and thus makes the fueling system, simple, compact and less expensive. This integrated gasoline pump injector (GPI) is aimed at catering to the upcoming stringent emission norms, as it enables the usage of closed-loop fuel correction with the help of an electronic control unit (ECU), based on the exhaust lambda feedback. A solenoid and spring arrangement is used in this injector design, where the fuel gets pressurized in a pumping chamber, and the pressurized fuel is then injected through orifices to produce spray in the intake port. Two concepts are used for pressurizing the fuel. First concept uses a spring to pump the fuel and a solenoid to retract the plunger. Second concept uses solenoid to pump the fuel and spring to retract the plunger.
2017-09-04
Technical Paper
2017-24-0046
Richard Stone, Ben Williams, Paul Ewart
The increased efficiency and specific output with Gasoline Direct Injection (GDI) engines are well known, but so too are the higher levels of Particulate Matter emissions compared with Port Fuel Injection (PFI) engines. To minimise Particulate Matter emissions, then it is necessary to understand and control the mixture preparation process, and important insights into GDI engine combustion can be obtained from optical access engines. Such data is crucial for validating models that predict flows, sprays and air fuel ratio distributions. Mie scattering can be used for semi-quantitative measurements of the fuel spray and this can be followed with Planar Laser Induced Fluorescence (PLIF) for determining the air fuel ratio and temperature distributions. With PLIF, very careful in-situ calibration is needed, and for temperature this can be provided by Laser Induced Thermal Grating Spectroscopy (LITGS).
2017-09-04
Technical Paper
2017-24-0110
Lucio Postrioti, Giulio Caponeri, Giacomo Buitoni
In the current automotive scenario, Direct Gasoline Injection technology is quickly spreading in several markets due to its higher potential for the fulfillment of stringent CO2 emission regulations. The stringent efficiency targets achievement is enabled by engine downsizing and by stratified-charge combustion strategy implementation; both these technologies are based on direct injection technology. Consequently, the fuel injector represents one of the key components for present and next SI engines. Along with appropriate spray characteristics in terms of sizing and jets shape and penetration in the combustion chamber, an accurate instantaneous injection rate control is required particularly to actuate complex multi-event injector actuation strategies.
2017-09-04
Technical Paper
2017-24-0031
Imre Gergely Nagy, Andrea Matrisciano, Harry Lehtiniemi, Fabian Mauss, Andreas Schmid
Large two-stroke marine diesel engines have special injector geometries, which differ substantially from the configurations used in most other Diesel engine applications. One of the major differences is that injector orifices are distributed in a highly non-symmetric fashion that affects the spray morphology. Earlier investigations demonstrated the dependency of the spray morphology on the location of the spray orifice, and therefore on the resulting flow conditions at the nozzle tip. Thus, spray structure is directly affected by the flow structure within the orifice [1]. Following recent LES resolved spray primary breakup studies [2], the present paper focuses on spray secondary breakup modelling of asymmetric spray structures in Euler-Lagrangian framework based on previous droplet distributions of primary breakup. Firstly, the derived droplet distributions are assigned via user coding to RANS 3D-CFD simulation of two nozzle bore geometries having 0.0 and 1.1 mm eccentricity.
2017-09-04
Journal Article
2017-24-0041
Daniele Piazzullo, Michela Costa, Luigi Allocca, Alessandro Montanaro, Vittorio ROCCO
In gasoline direct injection (GDI) engines, dynamics of the possible spray-wall interaction are key factors affecting the air-fuel mixture distribution and equivalence ratio at spark timing, hence influencing the development of combustion and the pollutants formation at the exhaust. Gasoline droplets impact may rebound with consequent secondary atomization or deposit in the liquid phase over walls as a wallfilm. This last slowly evaporate with respect to free droplets, leading to local enrichment of the mixture, hence to increased unburned hydrocarbons and particulate matter emissions. In this scenario, complex phenomena characterize the turbulent multi-phase system where heat transfer involves the gaseous mixture (made of air and gasoline vapour), the liquid phase (droplets not yet evaporated and wallfilm) and the solid wall, especially in the so-called wall-guided mixture formation mode.
2017-09-04
Technical Paper
2017-24-0044
Jeremy Rochussen, Jeff Son, Jeff Yeo, Mahdiar Khosravi, Patrick Kirchen, Gordon McTaggart-Cowan
Alternative fuel injection systems and advanced in-cylinder diagnostics are two important tools for engine development; however, the rapid and simultaneous achievement of these goals is often limited by the space available in the cylinder head. Here, a research-oriented cylinder head is developed for use on a single cylinder 2-litre engine, and permits three simultaneous in-cylinder combustion diagnostic tools (cylinder pressure measurement, infrared (IR) absorption, and multi-color pyrometry). In addition, a modular injector mounting system enables the use of a variety of direct fuel injectors for both gaseous and liquid fuels. The design of the all-new cylinder head was derived from a production cylinder head, which was sectioned and laser scanned to create a parametric model.
2017-09-04
Technical Paper
2017-24-0048
Jose V. Pastor, Jose M. Garcia-Oliver, Antonio Garcia, Mattia Pinotti
In the past few years various studies have shown how the application of a highly premixed dual fuel combustion for CI engines leads a strong reduction for both pollutant emissions and fuel consumption. In particular a drastic soot and NOx reduction were achieved. In spite of the most common strategy for dual fueling has been represented by using two different injection systems, various authors are considering the advantages of using a single injection system to directly inject blends in the chamber. In this scenario, a characterization of the behavior of such dual-fuel blend spray became necessary, both in terms of inert and reactive ambient conditions. In this work, a light extinction imaging (LEI) has been performed in order to obtain two-dimensional soot distribution information within a spray flame of different diesel/gasoline commercial fuel blends. All the measurements were conducted in an optically accessible two-stroke engine equipped with a single-hole injector.
2017-09-04
Technical Paper
2017-24-0069
Hyunwook Park, Jugon Shin, Choongsik Bae
Spray and combustion characteristics of diesel fuel were investigated in order to get a better understanding of the evaporation and combustion behavior under simulated cold-start conditions of a diesel engine. The experiment was conducted in a constant volume combustion chamber and the target ambient conditions were selected as the engine cranking. Mie scattering and shadowgraph techniques were conducted to visualize the liquid and vapor phase of the fuel under non-combustion condition (O2 concentration=0%). In-chamber pressure and direct flame visualization were acquired for spray combustion condition (O2 concentration=21%). The fuel was injected with an injection pressure of 30MPa, which is a typical value during cranking period. The liquid penetration of the fuel was increased at 573K of ambient temperature compared to that at 663K due to the poor evaporation characteristic and the increased fuel viscosity from the lower fuel temperature.
2017-09-04
Journal Article
2017-24-0067
Yoshiaki Toyama, Nozomi Takahata, Katsufumi Kondo, Tetsuya Aizawa
In order to better understand in-flame diesel soot oxidation processes, soot particles at the oxidation-dominant periphery of diesel spray flame were sampled by a newly developed “suck” type soot sampler employing a high-speed solenoid valve and their morphology and nanostructure were observed via High-Resolution Transmission Electron Microscopy (HR-TEM). A single-shot diesel spray flame for the soot sampling experiment was achieved in a constant-volume vessel under a diesel-like condition. The sampler quickly sucks out a small portion of soot laden gases from the flame. A TEM grid hold inside the flow passage close to its entrance is immediately exposed to the gas flow induced by the suction at the upstream of the solenoid valve, so that the quick thermophoretic soot deposition onto the grid surface can effectively freeze morphology variation of soot particles during the sampling processes.
2017-09-04
Technical Paper
2017-24-0073
Carlo Beatrice, Giacomo Belgiorno, Gabriele Di Blasio, Ezio Mancaruso, Luigi Sequino, Bianca Maria Vaglieco
Technologies for direct injection of fuel in compression ignition engines are in continuous development in order to get an increasingly high injection pressure. One of the most investigated component of this system is the injector; in particular, main attention is given to the nozzles characteristics as diameter, number, angle, internal shape. The reduction of nozzle hole diameter seems the simplest way to increase the fuel velocity and to promote the atomization process. On the other hand, the number of the holes must increase to keep the desired mass flow. On this basis, a new logic has been applied for the development of the next generation of injectors. The tendency to increase the nozzle number and to reduce the diameter has led to the replacement of the nozzle with a circular plate that moves vertically. The plate motion allows to obtain a cylindrical surface for the delivery of the fuel on 360° degrees; while the plate lift is calibrated to obtain the desired fuel mass flow.
2017-09-04
Technical Paper
2017-24-0115
Martin Pechout, Jan Czerwinski, Martin Güdel, Michal Vojtisek-Lom
In this study, the combustion of butanol, neat and mixed with gasoline, was investigated on a 0.6 liter two-cylinder spark ignition engine with fully adjustable fuel injection and spark timing, coupled with an eddy current dynamometer. Two isomers of butanol, n-butanol and iso-butanol, were examined. Butanol can be produced from non-food renewable resources and is one of the fuels exploited in the search of energy security and independence and of replacement of fossil fuels. Compared to the traditionally used ethanol, butanol does not exhibit hygroscopic behaviour, is chemically less aggressive and has higher energy density. On other hand, different laminar burning velocity and higher boiling temperature of butanol, compared to gasoline, requires some countermeasures to keep the engine operation reliable and efficient.
2017-09-04
Technical Paper
2017-24-0103
Marlene Wentsch, Marco Chiodi, Michael Bargende
Abstract Main limiting factor in the application of 3D-CFD simulations within an engine development is the very high time demand, which is predominantly influenced by the number of cells within the computational mesh. Arbitrary cell coarsening, however, results in a distinct distortion of the simulation outcome. It is rather necessary to adapt the calculation models to the new mesh structure in order to ensure reliability and predictability of the 3D-CFD engine simulation. In the last decade, a fast response 3D-CFD tool was developed at FKFS in Stuttgart. It aims for a harmonized interaction between computational mesh, implemented calculation models and defined boundary conditions in order to enable fast running simulations for engine development tasks. Their susceptibility to errors is significantly minimized by various measures, e.g. extension of the simulation domain (full engine) and multi-cycle simulations.
2017-09-04
Technical Paper
2017-24-0101
Pedro Marti-Aldaravi, Kaushik Saha, Jaime Gimeno, Sibendu Som
Abstract Actual combustion strategies in internal combustion engines rely on fast and accurate injection systems to be successful. One of the injector designs that has shown good performance over the past years is the direct-acting piezoelectric. This system allows precise control of the injector needle position and hence the injected mass flow rate. Therefore, understanding how nozzle flow characteristics change as function of needle dynamics helps to choose the best lift law in terms of delivered fuel for a determined combustion strategy. Computational fluid dynamics is a useful tool for this task. In this work, nozzle flow of a prototype direct-acting piezoelectric has been simulated by using CONVERGE. Unsteady Reynolds-Averaged Navier-Stokes approach is used to take into account the turbulence. Results are compared with experiments in terms of mass flow rate. The nozzle geometry and needle lift profiles were obtained by means of X-rays in previous works.
2017-09-04
Technical Paper
2017-24-0105
Stefania Falfari, Gian Marco Bianchi, Giulio Cazzoli, Claudio Forte PhD, Sergio Negro
Abstract The primary target of the internal combustion engines design is to lower the fuel consumption and to enhance the combustion process quality, in order to reduce the raw emission levels without performances penalty. In this scenario the direct injection system plays a key role for both diesel and gasoline engines. The spray dynamic behaviour is crucial in defining the global and the local air index of the mixture, which in turns affects the combustion process development. At the same time it is widely recognized that the spray formation is influenced by numerous parameters, among which also the cavitation process inside every single hole of the injector nozzle. The proper prediction of the cavitation development inside the injector nozzle holes is crucial in predicting the liquid jet emerging from them.
2017-09-04
Technical Paper
2017-24-0108
Alessandro Montanaro, Marianna Migliaccio, Luigi Allocca, Carlo Beatrice, Valentina Fraioli, Roberto Ianniello
Abstract In the present paper, a new concept of open nozzle spray was investigated as possible application for compression ignition engines. The study concerns an experimental and numerical characterization of a spray generated through a prototype high-pressure hollow-cone nozzle (HCN). The experimental description of the injection process was carried out under evaporative and non-evaporative conditions injecting the fuel in a constant-volume combustion vessel controlled in pressure and temperature in order to measure the spatial and temporal fuel pattern at engine-like gas densities. OpenFOAM libraries in the lib-ICE version of the numerical code were employed for simulating the spray dynamics after a first validation phase based on the experimental data. Results show a typical spray structure of the outward-opening nozzle with the overall fluid-dynamic arrangement having a good fuel distribution along the hollow-cone geometry but showing a reduced spatial penetration.
2017-09-04
Journal Article
2017-24-0152
Mirko Baratta, Daniela Misul, Jiajie Xu, Alois Fuerhapter, Rene Heindl, Cesare Peletto, Jean Preuhs, Patrick Salemi
The present paper is the outcome of the research activity carried out by Centro Ricerche Fiat, Politecnico di Torino, Delphi and AVL within the Gason research project of the EC (H2020 program). The overall goal of the research project is to develop CNG-only SI engines which are able to comply with post-EuroVI emission regulations and 2020+ CO2 emission targets, with reference to the new homologation cycle and real driving conditions. The work presented in this paper aimed at developing a small displacement turbocharged engine, which combines the advanced VVA MultiAir system for the air metering with the direct injection of natural gas. The activity focused on the development and fluid-dynamic characterization of the gaseous-fuel injector. Moreover, the combined use of CFD analysis and optical-access PLIF experimental techniques allowed the design of the combustion chamber to be optimized from the mixture formation point of view.
2017-09-04
Technical Paper
2017-24-0106
Alessandro Montanaro, Luigi Allocca, Amedeo Amoresano, Giuseppe Langella
Abstract The analysis of a spray behavior is confined to study the fluid dynamic parameters such as axial and radial velocity of the droplets, size distribution of the droplets, and geometrical aspect as the penetration length. In this paper, the spray is considered like a dynamic system and consequently it can be described by a number of parameters that characterize its dynamic behavior. The parameter chosen to describe the dynamic behavior is the external cone angle. This parameter has been detected by using an experimental injection chamber, a multi-hole (8 holes) injector for GDI applications and recorded by a high-speed C-Mos camera. The images have been elaborated by a fuzzy logic and neural network algorithm and are processed by using a chaos deterministic theory. This procedure carries out a map distribution of the working point of the spray and determines the stable (signature of the spray) and instable behavior.
2017-09-04
Technical Paper
2017-24-0107
Alessandro Montanaro, Luigi Allocca, Vittorio Rocco, Michela Costa, Daniele Piazzullo
Abstract Gasoline direct injection (GDI) engines are characterized by complex phenomena involving spray dynamics and possible spray-wall interaction. Control of mixture formation is indeed fundamental to achieve the desired equivalence ratio of the mixture, especially at the spark plug location at the time of ignition. Droplet impact on the piston or liner surfaces has also to be considered, as this may lead to gasoline accumulation in the liquid form as wallfilm. Wallfilms more slowly evaporate than free droplets, thus leading to local enrichment of the charge, hence to a route to diffusive flames, increased unburned hydrocarbons formation and particulate matter emissions at the exhaust. Local heat transfer at the wall obviously changes if a wallfilm is present, and the subtraction of the latent heat of vaporization necessary for secondary phase change is also an issue deserving a special attention.
2017-09-04
Technical Paper
2017-24-0113
Ezio Mancaruso, Luigi Sequino, Bianca Maria Vaglieco, Maria Cristina Cameretti
Abstract The management of multiple injections in compression ignition (CI) engines is one of the most common ways to increase engine performance by avoiding hardware modifications and after-treatment systems. Great attention is given to the profile of the injection rate since it controls the fuel delivery in the cylinder. The Injection Rate Shaping (IRS) is a technique that aims to manage the quantity of injected fuel during the injection process via a proper definition of the injection timing (injection duration and dwell time). In particular, it consists in closer and centered injection events and in a split main injection with a very small dwell time. From the experimental point of view, the performance of an IRS strategy has been studied in an optical CI engine. In particular, liquid and vapor phases of the injected fuel have been acquired via visible and infrared imaging, respectively. Injection parameters, like penetration and cone angle have been determined and analyzed.
2017-09-04
Technical Paper
2017-24-0119
Jos Feijen, Gerard Klink, Ed Jong, Andreas Schmid, Niels Deen, Michael Boot
Abstract Second generation biomass is an attractive renewable feedstock for transport fuels. Its sulfur content is generally negligible and the carbon cycle is reduced from millions to tens of years. One hitherto non-valorized feedstock are so-called humins, a residual product formed in the conversion of sugars to platform chemicals, such as hydroxymethylfurfural and methoxymethylfurfural, intermediates in the production of FDCA, a building block used to produce the polyethylene furanoate (PEF) bottle by Avantium. The focus of this study is to investigate the spray combustion behavior of humins as a renewable alternative for heavy fuel oil (HFO) under large two-stroke engine-like conditions in an optically accessible constant volume chamber.
2017-09-04
Technical Paper
2017-24-0006
Alejandro Aljure, Xavier Tauzia, Alain Maiboom
Abstract Diesel engines are being more commonly used for light automotive applications, due to their higher efficiency, despite the difficulty of depollution and extra associated costs. They require more accessories to function properly, such as turbocharging and post-treatment systems. The most important pollutants emitted from diesel engines are NOx and particles (in conventional engines), being difficult to reduce and control because reducing one increases the other. Low temperature combustion (LTC) diesel engines are able to reduce both pollutants, but increase emissions of CO and HC. Besides HCCI and EGR systems, one method that could achieve LTC conditions is by using multiple injections (pilot/main, split injection, etc.). However, understanding multiple diesel injection is no easy task, so far done by trial and error and complex 3D CFD models, or too simplified by 0D models.
2017-09-04
Journal Article
2017-24-0012
Andrea Piano, Giulio Boccardo, Federico Millo, Andrea Cavicchi, Lucio Postrioti, Francesco Concetto Pesce
Abstract Nowadays, injection rate shaping and multi-pilot events can help to improve fuel efficiency, combustion noise and pollutant emissions in diesel engine, providing high flexibility in the shape of the injection that allows combustion process control. Different strategies can be used in order to obtain the required flexibility in the rate, such as very close pilot injections with almost zero Dwell Time or boot shaped injections with optional pilot injections. Modern Common-Rail Fuel Injection Systems (FIS) should be able to provide these innovative patterns to control the combustion phases intensity for optimal tradeoff between fuel consumption and emission levels.
2017-09-04
Technical Paper
2017-24-0025
Francesco Sapio, Andrea Piano, Federico Millo, Francesco Concetto Pesce
Abstract Development trends in modern Common Rail Fuel Injection System (FIS) show dramatically increasing capabilities in terms of optimization of the fuel injection pattern through a constantly increasing number of injection events per engine cycle along with a modulation and shaping of the injection rate. In order to fully exploit the potential of the abovementioned fuel injection pattern optimization, numerical simulation can play a fundamental role by allowing the creation of a kind of a virtual injection rate generator for the assessment of the corresponding engine outputs in terms of combustion characteristics such as burn rate, emission formation and combustion noise (CN). This paper is focused on the analysis of the effects of digitalization of pilot events in the injection pattern on Brake Specific Fuel Consumption (BSFC), CN and emissions for a EURO 6 passenger car 4-cylinder diesel engine.
2017-08-16 ...
  • August 16, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
The improved efficiencies of the modern diesel engine have led to its increased use within the mobility industry. The vast majority of these diesel engines employ a high-pressure common rail fuel injection system to increase the engine's fuel-saving potential, emissions reduction, and overall performance. This one-day seminar will begin with a review of the basic principles of diesel engines and fuel injection systems. Diesel and alternative fuels will be discussed, followed by current and emerging diesel engine applications.
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