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Viewing 1 to 30 of 16836
2015-09-06
Technical Paper
2015-24-2385
Guillaume Alix, Jean-Charles Dabadie, Gregory Font
Legal constraints concerning CO2 emissions have made the improvement of light duty vehicle efficiency mandatory. In result, vehicle powertrain and its development have become increasingly complex, requiring the ability to assess rapidly the effect of several technological solutions, such as hybridization or internal combustion engine (or ICE) downsizing, on vehicle CO2 emissions. In this respect, simulation is nowadays a common way to estimate a vehicle’s fuel consumption on a given driving cycle. This estimation can be done with the knowledge of vehicle main characteristics, its transmission ratio and efficiency and its internal combustion engine (ICE) fuel consumption map. While vehicle and transmission parameters are relatively easy to know, the ICE consumption map has to be obtained through either test bench measurements or computation.
2015-09-06
Technical Paper
2015-24-2390
Shashi Aithal, Stefan Wild
Design and optimization of automotive engines present unique challenges on account of the large design space and conflicting constraints. Optimizing the fuel consumption and reducing emissions over a driving cycle is a good example. Inlet pressure, equivalence ratio, humidity, EGR fraction, inlet air temperature, ignition timing, engine load, engine speed (RPM) etc. each impact fuel consumption and emissions and thus represent a vast parametric space to conduct de sign and global optimization studies. This large parametric space is further increased when one has to consider newer fuels and fuel-blends (varying ratios of fuel-additive mixtures) further complicating the design-optimization problem. The large design parameter space precludes the use of detailed numerical or experimental investigations. Physics-based reduced-order models (quasi-dimensional models) can be used effectively in the design and global optimization of such problems.
2015-09-06
Technical Paper
2015-24-2392
Vincenzo De Bellis, Luigi Teodosio, Daniela Siano, Fabrizio Minarelli, Diego Cacciatore
In this paper, a high performance V12 spark-ignition engine is experimentally investigated at test-bench in order to fully characterize its behavior in terms of both average and cycle-by-cycle performance parameters, for different operating conditions. In particular, for each considered point, a spark advance sweep is actuated, starting from a knock-free calibration, up to intense knock operation. Trains of 300 consecutive pressure cycles are acquired for each of the 12 cylinders, together with the main overall engine performance, including air flow, fuel flow, torque, pollutant emissions, and fuel consumption. Acquired data are statistically analyzed to derive the distributions of main indicated parameters (combustion phasing and duration, Indicated Mean Effective Pressure - IMEP, etc.) in order to find proper correlation with averaged quantities, collecting the findings of all the considered operating points and all the cylinders.
2015-09-06
Technical Paper
2015-24-2421
Federico Stola, Domenico Paolino, Marco Parotto, Fabio Troina
Current market drivers for automotive and light commercial engines and powertrain systems are mainly the new CO2 emission regulations all over the world and the pollutant emission reduction in the emerging markets, at minimal system cost. For both reasons, the adoption of a regulated electric low pressure fuel pump is very advantageous for electronically controlled diesel systems, customized for the emerging markets. Usually, the fuel delivery is performed at the maximum flow rate and a pressure regulator discharges the exceeding fuel amount from the rail or upstream the high pressure pump. At part load, the electric feed pump flow is higher than the request for engine power generation. For the purpose of this paper, the low pressure fuel pump is controlled for fuel delivery according to the engine request (reduced fuel consumption), thus avoiding the use of a pressure regulator valve (reduced cost).
2015-09-06
Technical Paper
2015-24-2461
Agnese Magno, Ezio Mancaruso, Bianca Maria Vaglieco
The diesel engine is currently the most efficient internal combustion engine technology. Moreover, in order to realize more efficient engine type could be convenient to combine this technology with one of the cleanest fuels available (methane). The main benefits are: methane (CH4) is cheaper than diesel and thus may reduce fuel costs; and, dual fuel technology also reduces particulate matter emissions. In the present activity, dual fuel operation was investigated in a single cylinder research engine. Methane was injected in the intake manifold while the diesel was delivered via the standard injector directly into the engine. The aim is to study the effect of increasing methane concentration at constant injected diesel amount on the start of combustion, ignition delay, and combustion evolution.
2015-09-06
Technical Paper
2015-24-2452
Benedikt Heuser, Sebastian Ahling, Florian Kremer, Stefan Pischinger, Hans Rohs, Bastian Holderbaum, Thomas Korfer
An experimental study has been carried out on dual-fuel operation with a Diesel engine for passenger car application. For these investigations, two very common fuels were chosen: For port fuel injection, the fuel used was gasoline (RON95, E10), for direct injection it was EN590 Diesel fuel. The experiments have been carried out almost in the whole engine load range from low part load at an indicated mean effective pressure (IMEP) of 0.43 MPa up to full load operation at an IMEP of 2.8 MPa. The engine speed was varied from 1500 rpm up to 4000 rpm. Within the relevant engine part load range, emissions of nitric oxides (NOx) were kept below the EU6 level at engine-out. At low part load, emissions of hydrocarbons (HC) and carbon monoxide (CO) as well as combustion stability are challenging in dual-fuel operation. Thus, the share of gasoline was limited to 60% m/m.
2015-09-06
Technical Paper
2015-24-2453
Abdul Rahman K, A Ramesh
Diesel fuelled HCCI (Homogeneous Charge Compression Ignition) engines experience advanced heat release rates and high HC emissions. However, gaseous fuel like biogas and hydrogen that have high self ignition temperatures have been used to effectively retard the combustion process in diesel fuelled HCCI engines. Since gaseous fuels form homogeneous mixtures more readily as compared to diesel they also can lower the HC and smoke emissions in HCCI engines. In biogas diesel HCCI engines the homogeneity of the diesel which is influenced by the injection process significantly affects combustion and performance. This work focuses on the influence of injecting diesel in two pulses in a Biogas Diesel HCCI (BDHCCI) engine as against injecting it in a single pulse. Comparisons have also been made with the Dual Fuel mode of operation at the same output under different biogas to diesel energy ratios.
2015-09-06
Technical Paper
2015-24-2511
Theodoros Grigoratos, Georgios Fontaras, Giorgio Martini, Cesare Pelleto
Gas operated Heavy Duty Vehicles (HDV) powered by Natural Gas (NG) are seen as a possible option for curbing CO2 emissions, fuel consumption and operating costs of goods transport. Initiatives have been adopted by various organizations worldwide in order to introduce NG fueled HDVs in their fleets. In this study, an advanced newly designed CNG prototype engine, which was developed in the framework of the FP7 research project “CO2 Reduction for long distance transport” (CO2RE), is benchmarked against its parent Euro V compliant CNG engine (reference) in terms of emissions and fuel consumption. The main technological innovation includes a new cylinder head equipped with a Variable Valve Actuation system designed to provide on the intake side a continuous fully flexible variation of the valve lift and timing. The newly developed engine was optimized for urban emission profiles and operation such as garbage collection purposes.
2015-09-06
Technical Paper
2015-24-2516
Panayotis Dimopoulos Eggenschwiler, Daniel Schreiber
Particulate matter (PM)in diesel exhaust is captured in diesel particulate filters (DPFs). Since increased PM load in the filter and thus increased pressure drop across the filter deteriorates the engine performance, the filter load of the DPF has to be removed during a process referred to as regeneration. Measures for successful regeneration aim at accelerating soot oxidation and increase fuel consumption. Regeneration lay-out and thus fuel consumption increase is strongly depending on the oxidation behavior of soot. The aim of the present study is the investigation of soot oxidation characteristics. Therefore particle filters have been loaded with soot using the exhaust gas of small heavy duty vehicle operated under defined conditions on an engine dynamometer. The particle filters have been then dismantled and fragmented on their constituting segments. Each filter segment has been regenerated individually in a specifically designed test bench.
2015-09-06
Technical Paper
2015-24-2519
Richard Cornwell, Huntly Thomas, Joshua Dalby, Phil Carden, Brian Knight, Andrew Ward, Grace Carr
Fuel consumption, and the physical behaviours behind it, have never been of greater interest to the automotive engineering community. The enormous design, development and infrastructure investment involved with a new engine family which will be in production for many years demands significant review of the base engine fundamental architecture. Future CO2 challenges are pushing car manufacturers to consider alternative engine configurations. As a result, a wide range of diesel engine architectures are available in production particularly in the 1.4 to 1.6L passenger car market, including cylinder size, number of valves per cylinder, and bore:stroke ratio. In addition, the 3 cylinder engine has recently entered the market, despite its historic NVH concerns. Ricardo has performed a generic architecture study for a midsize displacement engine in order to assess the pros and cons of each engine configuration.
2015-09-06
Technical Paper
2015-24-2535
Andreas Behn, Matthias Feindt, Gerhard Matz, Sven Krause, Marcus Gohl
The limitation of fuel ingress into the oil sump of an internal combustion engine during operation is important to preserve the tribological properties of the lubricant and limit component wear. On one side efficient simulation models are necessary to estimate the fuel ingress in an early stage of the development process. On the other side application and test engineers require effective tools to optimize the injection rates at the test cell. A sensitive and versatile measurement system is essential for this process. Important sampling positions for fuel concentration measurements while using a late post injection are the injector target, the cylinder liner below, the oil sump as well as the crankcase ventilation. While oil sampling from the sump and laboratory analysis is a common procedure, there is no system for automatic sampling of all the positions and fast online analysis of the samples.
2015-09-06
Technical Paper
2015-24-2543
Damien Maroteaux, Damien Le Guen, Eric Chauvelier
The worldwide trends for future CO2 regulation standards will push car manufacturers for more and more development of Electric and Hybrid Electric Vehicles. Many different configurations of Hybrid Electric Vehicles exist, including parallel hybrid, series hybrid, plug-in hybrids, Battery Electric Vehicles with Range Extender, etc. The choice of the optimal architecture depends on many different parameters, and is a key issue to be solved at the beginning of vehicle development. In order to help decision making in the early phase of projects, simulation tools are essential. A specific simulation platform for simulation of fuel economy and CO2 emissions for hybrid electric vehicles has been developed by Renault.
2015-09-06
Technical Paper
2015-24-2391
Dimitris Tsokolis, Stefanos Tsiakmakis, Georgios Triantafyllopoulos, Anastasios Kontses, Zisis Toumasatos, Georgios Fontaras, Athanasios Dimaratos, Biagio Ciuffo, Jelica Pavlovic, Alessandro Marotta, Zissis Samaras
The present paper describes the development of a standardized modelling approach to simulate the effect of the new Worldwide harmonised Light duty Test Procedure (WLTP) on the certified CO2 emissions of light duty vehicles. The European fleet has been divided into a number of representative segments based on specific vehicle characteristics and technologies. Representative vehicles for each segment were chosen. A test protocol has been developed in order to generate the necessary validation data for the simulation models which were developed subsequently. A standardized modelling procedure was adopted, in order to minimize the flexibilities and sources of uncertainty, which was based on the development of a reference "template model" to be used in the study. Subsequently, vehicle models were developed using AVL Cruise simulation software based on the abovementioned template model.
2015-09-06
Technical Paper
2015-24-2486
Ajay Singh Verma, Prof. M. Muzaffarul Hasan, Dr. Ashish Karnwal, Vipul Vibhanshu
The continuous growth of population and development of industries give rise to massive increase in the global energy demand in recent years. The timing of peak oil, serious social economic consequences and global decline in oil production may be avoided by use of unconventional alternative fuels. Therefore present work investigated the combustion and emission characteristics of an unmodified four stroke single cylinder variable compression ratio diesel engine utilizing isopropyl alcohol (2-propanol)-diethyl ether blends with diesel. In this study, the proportion of isopropyl alcohol was varied as 10%, 15% and 20% by volume while proportion of diethyl ether was kept constant as 5% by volume. The different fuel samples were prepared using 10% isopropyl, alcohol 5% diethyl ether by volume (IPD15), 15% isopropyl alcohol, 5% diethyl ether by volume (IPD20) and 20% isopropyl alcohol 5% diethyl ether by volume (IPD25) with neat standard diesel.
2015-09-06
Technical Paper
2015-24-2409
Lorenzo Bartolucci, Stefano Cordiner, Vincenzo Mulone, Vittorio Rocco, Edward Chan
Predictive modeling of the premixed turbulent combustion process has become key to design advanced strategies for novel internal combustion engine solutions. Reynolds Averaged Navier-Stokes (RANS) based combustion models are assessed but are unable to capture transient phenomena such combustion instabilities, self-ignition and other aspects related to the coupling between turbulence and chemistry. Large Eddy Simulation (LES) based combustion models have demonstrated in several studies better capabilities to capturing those phenomena and, hence, present in general much higher accuracy. The aim of this work is to carry out a statistical analysis of numerical results obtained with a LES approach to describe a partially premixed natural gas spark ignition combustion process in a Constant Volume Combustion Chamber (CVCC). The OpenFOAM based solver has been already validated in a previous paper by comparing results data experimentally gathered at the University of British Columbia.
2015-09-06
Technical Paper
2015-24-2499
Fabio Berni, Sebastiano Breda, Alessandro D'Adamo, Stefano Fontanesi, Giuseppe Cantore
A new generation of highly downsized SI engines with specific power outputs around or above 150 HP/liter is emerging in the sport car market sector. Technologies such as high-boosting, direct injection and downsizing are adopted to increase power density and reduce fuel consumption. To counterbalance the increased risks of pre-ignition, knock or mega-knock, currently made turbocharged SI engines usually operate with high fuel enrichments and delayed (sometimes negative) spark advances. The former is responsible for high fuel consumption levels, while the latter induce an even lower A/F ratio (below 11), to limit the turbine inlet temperature, with huge negative effects on BSFC. A possible solution to increase knock resistance is investigated in the paper by means of 3D-CFD analyses: water/methanol emulsion is port-fuel injected to replace mixture enrichment while preserving, if not improving, indicated mean effective pressure and knock safety margins.
2015-09-06
Technical Paper
2015-24-2473
Alessandro Montanaro, Luigi Allocca, Giovanni Meccariello, Maurizio Lazzaro
In internal combustion engines, the direct injection at high pressures produces a strong impact of the fuel on the combustion chamber wall, especially in small-bore sizes used for passenger cars. This effect is relevant for the combustion process resulting in an increase of the pollutant emissions and in a reduction of the engine performances. This paper aims to report the effects of the injection pressure and wall temperature on the macroscopic behavior and atomization of the impinging sprays on the wall. The gasoline spray-wall interaction was characterized inside an optically-accessible quiescent chamber using a novel make ready Z-shaped schlieren-Mie scattering set-up using a high-speed C-Mos camera as imaging system. The arrangement was capable to acquire alternatively the schlieren and Mie-scattering images in a quasi-simultaneous fashion using the same line-of-sight.
2015-09-06
Technical Paper
2015-24-2497
Pierpaolo Napolitano, Carlo Beatrice, Chiara Guido, Nicola Del Giacomo, Leonardo Pellegrini, Pietro Scorletti
The present paper describes the results of a research activity aimed at studying the potential effects determined by the use of Hydrotreated Vegetable Oil (HVO) blends as fuels in modern diesel engines. Five fuels were tested on a light duty four-cylinder diesel engine, Euro 5 version, installed on a dyno test bench. The set of fuels comprised a commercial EN590-compliant diesel fuel and four experimental fuels formulated ad hoc to investigate the effect of the cetane provided by the HVO. The experimental campaign included both dynamic test conditions, running the engine along the New European Driving Cycles (NEDC), and steady-state operating engine points, six at partial speed/loads conditions, representative of the urban and extra-urban part of the engine homologation cycle, and one at full load condition at 3500 rpm engine speed.
2015-09-06
Technical Paper
2015-24-2432
Michela Costa, Paolo Sementa, Ugo Sorge, Francesco Catapano, Guido Marseglia, Bianca Maria Vaglieco
Knocking combustion in spark ignition engines is an abnormal combustion phenomenon strongly affecting performance and thermal efficiency. The possibility to have abnormal combustions in a GDI (gasoline direct injection) engine is linked to the outcome of the mixture formation process. Present work explores possible advantages deriving from the use of split injections in increasing the engine power output and reducing the tendency to knock. Due to the recent development of gasoline injection systems, multiple injections are today regarded as a valuable tool to improve the in-chamber evaporation process and simultaneously reduce undesired effects deriving from an excessive spray impact over walls. Combustion stability is enhanced, unburned hydrocarbons and soot emissions are limited.
2015-09-06
Technical Paper
2015-24-2457
Robert Morgan, Penny Atkins, Andrew Atkins, Christopher Lenartowicz, Morgan Heikal
The recovery of waste heat from the vehicle exhaust has been proposed as a means of achieving future commercial vehicle CO2 emissions targets. Methods proposed include turbo compounding, Thermo Electric generation and the integration of a Rankine cycle with the vehicle system. In this paper, a novel alternative approach is proposed using fuel reforming. Thermal energy is recovered from the vehicle exhaust and used to provide the thermal input to steam reform part of the diesel fuel. The resulting reformate has a higher energy content than the diesel supplied to the reformer as the steam reforming process is endothermic. The reformate is then introduced to the engine intake system and mixed with diesel and burnt in the combustion chamber. As the overall fuel energy has increased through the conversation of thermal energy to chemical energy, the thermal efficiency of the engine is improved.
2015-09-06
Technical Paper
2015-24-2475
Donghoon Kim, Choongsik Bae, Stephen Park
Three visualization methods, Schlieren, Shadowgraph, Mie-scattering, were applied to compare diesel and gasoline spray structures. Fuels were injected into the high pressure/high temperature chamber under the same in-cylinder pressure and temperature condition of low load in a GDCI (gasoline direct injection compression ignition) engine. Two injection pressures (20 and 40 MPa), two ambient pressures (4.2MPa and 1.7 MPa) and two ambient temperature (908 K and 677 K) were selected. Three images from different methods were overlapped to show liquid and vapor phases more clearly. Vapor development of two fuels were similar, but different liquid developments were shown. At the same injection pressure and ambient temperature, gasoline liquid propagated more shortly and disappeared rapidly than diesel liquid phase. At the low ambient temperature and pressure condition, gasoline and diesel sprays with higher injection pressure showed a longer liquid length due to higher spray momentum.
2015-09-06
Technical Paper
2015-24-2498
Markku Aaro Kuronen, Ulla Kiiski, Kalle Lehto
Sulphur level of diesel fuel started to be limited in Europe at the end the 19th century. Quite soon it was noticed that the processes for removing sulphur also removed other polar material and the natural lubricity of the diesel fuel was lost. Lubricity additives were introduced to bring the lubricity back to a certain level. Also, a rapid laboratory method was developed to measure lubricity i.e. High Frequency Reciprocating Rig (HFRR). The method (HFRR) ISO 12156-1 was introduced in 1997. In recent years purely paraffinic diesel fuels, such as GTL (Gas To Liquid) and renewable HVO (Hydrotreated Vegetable Oil), have been introduced to the market. Unlike traditional biodiesel (FAME, Fatty Acid Methyl Ester), paraffinic diesel fuels require the use of lubricity additives to reach a sufficient level of lubricity. The aim of this study was to investigate how the current lubricity additives work as a function of aromatic content in diesel.
2015-09-06
Technical Paper
2015-24-2505
Maria Rosaria Gaballo, Maria Giodice, Alberto Diano, Fabio Fersini, Francesco Miccolis, Soenke Mannal, Stefan Motz
World of diesel becomes technically more and more complex due to the increasingly restrictive legislation e.g. with respect to emissions, fuel consumption and RDE (real driving emissions evaluations). Simulation provides a mechanism for the investigation and optimization of diesel engine performances, evaluation and investigation of innovative new engine concepts, RDE evaluation, after-treatment design and optimization, by that contributing to solve above mentioned challenges. Besides these generally valid capabilities of simulations our model development is focused additionally on the mission to use right sized models to reduce usage of resources and by that making simulation an even more rapid and cost effective method In this contribution we present our approach for simulation as an advanced integrated tool capable to answer challenging questions towards emission and fuel consumption reduction in future legislation frameworks.
2015-09-06
Technical Paper
2015-24-2459
Francesco Catapano, Silvana Di Iorio, Paolo Sementa, Bianca Maria Vaglieco
The increasing concerns on the global environment issues and on the depletion of fossil fuel reserves have been driving to searching sustainable and environmental friendly fuels. Methane is one of the alternative fuels for addressing these issues. The potential of methane in improving the engine performance was fully exploited when blended with hydrogen or dual fueled with gasoline. In this paper a methane-assisted gasoline injection in a small displacement GDI SI engine was analyzed. Typically, the air-assisted fuel injection system was applied to supply assistant air for the atomization of injected fuel. This configuration allows improving the gasoline combustion thanks not only to the assisted injection, which improves the fuel atomization and consequently the homogenization of the charge, but also to the presence of the methane and its chemical interaction with gasoline heavy hydrocarbon, which allows a more efficient combustion.
2015-09-06
Technical Paper
2015-24-2449
Mark Aaron Hoffman, Zoran Filipi
The limited operational range of Homogeneous Charge Compression Ignition engines is influenced by combustion chamber deposit accumulation and burn-off. Previous works have investigated in-situ combustion chamber deposit thermal properties with the end goal of replicating their increased temperature swing during compression and operability range shift in a manner which is independent of driving cycle. Combustion chamber deposit thermal diffusivity was found to differ depending on the location of deposit accumulation within the combustion chamber. These material property differences have been attributed to the spatially dependent interaction of deposits with the cylinder charge. This work establishes the methodology for determining the impact of directly injected gasoline on in-situ combustion chamber deposit thermal diffusivity.
2015-09-06
Technical Paper
2015-24-2479
Maximilian Malin, Vladimir Krivopolianskii, Bjørn Rygh, Vilmar Aesoy, Eilif Pedersen
Maritime environmental restrictions urge the need for cleaner emissions from shipping, by improved combustion processes, alternative cleaner fuels and exhaust gas cleaning. Alternative fuels, like bio fuel (fish oil), has a potential to reduce soot production during the combustion process and will be deeply investigated in this article. For this purpose a constant volume pre-combustion rig laboratory was build up in the last year and is used as a basic investigation tool for studying the fuel injection system (including investigation in combustion, spray development, fuel evaporation process and ignition delay) in engines. The focus of this study is to investigate the injector in full size, including experiments with multi nozzle injections, and with full optical access to the chamber. To generate similar injection condition in the combustion rig as in the internal combustion engine, the rig is heated up using a so called chemical heating process.
2015-09-06
Journal Article
2015-24-2393
Fabio Bozza, Vincenzo De Bellis, Fabrizio Minarelli, Diego Cacciatore
The results of the experimental analyses described in the Part 1 of the paper, are here employed to build up an innovative numerical approach for the 1D modeling of combustion and knock of a high performance 12-cylinders spark-ignition engine. The whole engine is schematized in detail in a 1D framework simulation, developed in the GT-PowerTM environment. Proper “in-house developed” sub-models are used to describe the combustion process, turbulence phenomenon and the knock occurrence. In particular, the knock onset is evaluated by a TRF chemical kinetic scheme, coupled to the combustion model and able to detect the presence of auto-ignition reactions in the end-gas zone. A refined in-cylinder heat transfer model is adopted, based on a modified Woschni correlation. Wall temperature distributions are computed based on a proper specification of the heat transfer coefficients of the cooling water and lubricant oil.
2015-09-06
Journal Article
2015-24-2458
Yasumasa Suzuki, Taku Tsujimura, Takuro Mita
Hydrogen can be produced by electrolyzation with renewable electricity and the combustion products of hydrogen mixture include no CO, CO2 and unburned hydrocarbons. We focus these characteristics and high thermal efficiency of diesel engine. In this study, hydrogen diesel dual fuel (H2 DDF) operation on multi-cylinder diesel engine is investigated due to clarify advantages and disadvantages of H2 DDF. Firstly, we evaluate performances of H2 DDF operation without EGR under several brake power conditions. Proportion of hydrogen to total input energy (H2 rate) is changed by adjusting diesel fuel amount to keep torque constant. Under low load conditions, DDF operation improve CO2, CO, THC emissions. However, NOx, soot emission and thermal efficiency get worse. Unburned hydrogen emission causes the worse thermal efficiency. As engine loads increase, H2 rate of 80% can be achieved and thermal efficiency of DDF is higher than one of diesel fuel operation.
2015-09-06
Journal Article
2015-24-2513
Michal Vojtisek-Lom, Vit Beranek, Jitka Stolcpartova, Martin Pechout, Vojtech Klir
*** This paper is also relevant to session ICENA303, Alternative and Advanced Fuels *** This work reports on the effects of using butanol, an alternative to ethanol, in an unmodified production direct injection spark ignition (DISI) engine. Butanol, a higher alcohol that can be produced from biomass by fermentation, is an emerging alternative fuel viewed as more compatible with gasoline engines and fuel systems than ethanol. In this work, a Euro 5 Ford Focus car with a 1.0-liter Ecoboost DISI engine has been tested on a chassis dynamometer using WLTP and Artemis driving cycles, and on the road on a one-hour test loop containing urban, rural and motorway driving. Two isomers of butanol, 1-butanol and 2-methyl-propanol, were each blended with gasoline at 25% volume corresponding to 5% oxygen by weight or 15% ethanol (E15). Non-oxygenated gasoline and E15 were used as reference fuels. The vehicle performed well in terms of cold start, driveability, and general performance.
2015-06-15
Technical Paper
2015-01-2081
Hossein Habibi, Graham Edwards, Liang Cheng, Haitao Zheng, Adam Marks, Vassilios Kappatos, Cem Selcuk, Tat-Hean Gan
Abstract Icing conditions in cold regions of the world may cause problems for wind turbine operations, since accreted ice can reduce the efficiency of power generation and create concerns regarding ice-shedding. This paper covers modelling studies and some experimental development for an ongoing ice protection system that provides both deicing and anti-icing actions for wind turbine blades. The modelling process contained two main sections. The first part involved simulation of vibrations with very short wavelength or ultrasonic guided waves (UGW) on the blade to determine optimal excitation frequency and transducer configuration. This excitation creates horizontal shear stress at the interface between ice and blade and focuses energy at the leading edge for de-bonding ice layers.
Viewing 1 to 30 of 16836