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Technical Paper

Optimization of CI Engine Performance and Emissions Fueled by Blends of Alternative Fuels Methyl Ester Using Taguchi and Multi Regression Analysis

2019-09-16
2019-01-1893
Today’s frenetic engine manufacturing and transportation sector and its related traces viz; noise and vibration of our modern societies has adverse effect on environment as well as all of us. Modern research affords us the opportunity to understand the subject better and to develop advance technologies. Widely immediate slogan and goal of all industries might be to improve the performance and reduce emission using alternative fuel while, make the quietest and smoothest running Engines. To, reduce the dependency on diesel fuel (Due to rapid worldwide depletion) Biodiesel is one of the immediate, alternative and complimentary solution. In the Present study, to optimize the operating parameters of the Direct Injection Single Cylinder (5.2 kw) CI engine with respect to Brake Thermal Efficiency (BTE), Carbon monoxide (CO), Oxides of Nitrogen, Hydrocarbons (HC) etc..
Technical Paper

Electromagnetic Characteristic Comparison of Superconducting Synchronous Motors for Electric Aircraft Propulsion Systems

2019-09-16
2019-01-1912
Aircraft service has been increasing today and it also results in the increase of the greenhouse gas emission. To solve this problem, the electric aircraft propulsion system is the key solutions to realize the clean and high efficiency aircraft, while demanding higher output density motors. So far, though 5 kW/kg is realized with permanent magnet type synchronous motors, the electric aircraft for over 100 passengers demands motors with 16 -20 kW/kg. Superconducting (S.C.) technology is one of the effective candidates for higher output density motors. In comparison with copper wires, the S.C. wires have higher current density at less than –200 ℃. And we can make a lighter weight coil with the S.C. wires. So far, many groups have been studying the S.C. motors over 16 kW/kg. Generally, there are two kinds of S.C motors. One is the S.C. motors made of the S.C. field coils and copper armature windings. The other is the fully S.C. motors using S.C. field and armature windings.
Training / Education

Fuel Systems Material Selection and Compatibility with Alternative Fuels

2019-08-27
This course will introduce the participants to the factors governing fuel-material compatibility and methods to predict and empirically determine compatibility for new alternative fuel chemistries.  By understanding the mechanisms and factors associated with chemically-induced degradation, participants will be able to assess the impact of fuel chemistry to infrastructure components, including those associated with vehicle fuel systems.  This course is unique in that it looks at compatibility from a fuel chemistry perspective, especially new fuel types such as alcohols and other biofuels. 
Technical Paper

Impact of ethanol and aromatic hydrocarbons content on particulate emissions from a gasoline vehicle

2019-08-15
2019-24-0160
The impact of transport on global and local pollution have resulted in stricter emission limits. More specifically, increasing attention is being paid to particulate emissions at the exhaust gases in spark ignition engines. The particulate formation is mainly affected by: 1-fuel properties, 2-engine and fuel system characteristics and 3-Exhaust after-treatment system. In order to estimate the influence of fuel characteristics on particulate emissions, several research works have proposed fuel indices that correlate some of the fuel physical and chemical properties with engine particulate emissions. This work investigates the impact of fuel composition on particulate emissions and evaluates the Particulate Matter Index (PMI) proposed by Aikawa et. al, and other fuel indices, in terms of agreement with vehicle test bed results for a passenger car.
Technical Paper

Numerical Simulation of Syngas Blends Combustion in a Research Single-Cylinder Engine

2019-08-15
2019-24-0094
Despite syngas is a promising alternative fuel for internal combustion engines (ICEs), its extensive adoption has not been adequately investigated so far. The dedicated literature offers several fundamental studies dealing with H2/CO blends burning at high pressure and room temperature, as well as preheated mixture at low pressure. However, these thermodynamic states are far from the operational conditions typical of ICEs. Therefore, it is essential to investigate the syngas combustion process at engine-like conditions to shed light on this fuel performance, in order to fully benefit from syngas characteristics in ICE application. One of the key properties to characterize a combustion process is laminar flame speed, which is also used by the most widespread turbulent combustion models.
Technical Paper

Integrated CFD-Experimental Methodology for the Study of a Dual Fuel Heavy Duty Diesel Engine

2019-08-15
2019-24-0093
This paper deals with the experimental and numerical investigation of a 2.0 litre single cylinder Heavy Duty Diesel Engine fuelled by natural gas and diesel oil in Dual Fuel mode. Due to the gaseous nature of the main fuel and to the high compression ratio of the diesel engine, reduced emissions can be obtained. An experimental study has been carried out at three different load level (25%, 50% and 75% of full engine load). Basing on experimental data, the authors’ methodology is based on the use of one-dimensional and 3-dimensional models. The former is able to perform the whole engine with faster simulations while the latter can study deeply the even more complex phenomena (turbulence, combustion, etc.), due to the presence and to the interaction of the two fuels, which occur in the cylinder for the most interesting operating conditions.
Technical Paper

A coupled tabulated kinetics and flame propagation model for the simulation of fumigated medium speed dual-fuel engines

2019-08-15
2019-24-0098
The present work describes the numerical modeling of medium-speed marine engines, operating under a fumigated dual-fuel concept, i.e. with the second fuel injected in the ports. Due to the need to reduce engine-out emissions while maintaining engine efficiency, manufacturers are investigating new engine technologies. In the maritime industry, a promising technology to achieve these goals is that of fumigated dual-fuel engines, allowing a large amount of diesel to be replaced by a premixed fuel. To fully optimize the operational parameters of such a large maritime engine, computational fluid dynamics can be very helpful. Accurately describing the combustion process in such an engine is key, as the prediction of the heat release and the pollutant formation is crucial. Auto-ignition of the diesel fuel needs to be captured, followed by the combustion and flame propagation of the premixed fuel.
Technical Paper

A Study of Lean Burn Pre-chamber Concept in a Heavy Duty Engine

2019-08-15
2019-24-0107
Due to stringent emission standards, the demand for higher efficiency engines has been unprecedentedly high in recent years. Among several existing combustion modes, pre-chamber initiated combustion emerges to be a potential candidate for high-efficiency engines. Research on the pre-chamber concept exhibit higher indicated efficiency through lean limit extension while maintaining the combustion stability. In this study, different pre-chamber geometries were tested in a single-cylinder heavy-duty engine at different loads. The geometries were prepared with three different pre-chamber volumes and with three varying nozzle area to pre-chamber volume ratios. The pre-chambers were fueled with methane while two sets of experiments were conducted, the first with ethanol as main chamber fuel and the second with methane.
Technical Paper

Knock and Pre-ignition limits on utilization of Ethanol in Octane–on–Demand concept

2019-08-15
2019-24-0108
Octane-on-Demand (OoD) is a viable technology for reducing global greenhouse emissions from automobiles. The concept utilizes a low-octane fuel for most operating conditions. Previous research has focused on the minimum ethanol content required for achieving a specific load at a given speed as the low-octane fuel becomes knock limited as the load increases. However, it is also widely known that ethanol has a high tendency to pre-ignite, attributed by few to its high laminar flame speed and surface ignition tendency. Moreover, ethanol has a lower calorific value, requiring a larger fuel mass to be injected to achieve similar power. A larger fuel mass increases the oil dilution by the liquid fuel, creating precursors for pre-ignition. Hence the limits on ethanol addition owing to pre-ignition also needs consideration before the technology can be implemented.
Technical Paper

Influence of Injection Strategies on Engine Efficiency for a Methanol PPC Engine

2019-08-15
2019-24-0116
Partially premixed combustion (PPC) is one of several advanced combustion concepts for the conventional diesel engine. PPC uses a separation between end of fuel injection and start of combustion, also called ignition dwell, to increase the mixing of fuel and oxidizer. This has been shown to be beneficial for simultaneously reducing harmful emissions and fuel consumption. The ignition dwell can be increased by means of exhaust gas recirculation (EGR) or lower intake temperature. However, the most effective means is to use a fuel with high research octane number (RON). Methanol has a RON of 109 and a recent study found that methanol can be used effectively in PPC mode, with multiple injections, to yield high brake efficiency. However, the early start of injection (SOI) timings in this study were noted as a potential issue due to increased combustion sensitivity. Therefore, the present study attempts to quantify the changes in engine performance for different injection strategies.
Technical Paper

Literature Review on dual-fuel combustion modelling

2019-08-15
2019-24-0120
In the search for low greenhouse gas propulsion, the dual fuel engine provides a solution to use low carbon fuel at diesel-like high efficiency. Also a lower emission of NOx and particles can be achieved by replacing a substantial part of the diesel fuel by for example natural gas. Limitations can be found in excessively high heat release rate (combustion-knock), and high methane emissions. These limitations are strongly influenced by operating parameters and properties of the used (bio)-gas. To find the dominant relations between fuel properties, operating parameters and the heat release rate and methane emissions, a combustion model is beneficial. Such a model can be used for optimizing the process, or can even be used in real time control. As precursor for such a model, the current state of art of dual fuel combustion modelling is investigated in this work. The focus is on high speed dual fuel engines for heavy duty and marine applications, with a varying gas/diesel ratio.
Technical Paper

Experimental Investigation of Combustion Characteristics in a Heavy-Duty Compression-Ignition Engine Retrofitted to Natural-Gas Spark-Ignition Operation

2019-08-15
2019-24-0124
The conversion of existing diesel engines to natural gas operation can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. Diesel compression ignition engines can be modified to NG spark ignition, by replacing the diesel injector with a NG spark plug and by fumigating NG in the intake manifold, to increase utilization of natural gas heavy-duty transportation sector. As the original diesel piston is maintained during conversion to decrease engine modification cost, the major of this study was to investigate the lean-burn characteristic of natural gas burning in this bowl-in-piston combustion chamber, which can accelerate the introduction of heavy-duty natural gas vehicles. Data analysis from engine experiments that changed spark timing indicated a two-stage combustion process in such retrofitted engines, which is different from traditional spark ignition engines.
Technical Paper

1D Modeling of Alternative Fuels Spray in a Compression Ignition Engine using Injection Rate Shaping Strategy

2019-08-15
2019-24-0132
The Injection Rate Shaping consists in a novel injection strategy to control air-fuel mixing quality via a suitable variation of injection timing that affects the injection rate profile. This strategy has already provided to be useful to increase combustion efficiency and reduce pollutant emissions in the modern compression ignition engines fed with fossil Diesel fuel. But today’s, the ever more rigorous emission targets are enhancing a search for alternative fuels and/or new blends to replace conventional ones, leading in turn a change in the air-fuel mixture formation. In this work a 1D model aims to investigate the combined effects of both Injection Rate Shaping and alternative fuels on the air-fuel mixture formation in a compression ignition engine. In a first step, a ready-made model for conventional injection strategies has been set up for the Injection Rate Shaping.
Technical Paper

Direct Injection Compression-Ignition Diesel-Methanol Blends Engine for Non-road Applications

2019-08-15
2019-24-0139
It is a promising approach to use methanol as a clean and low carbon alternative fuel for the non-road energy utilization sector and ultimately for the fight against the global climate change. This paper presents a numerical simulation of the performance and emission characteristics of neat methanol and diesel/methanol dual fuel combustion processes based on Yuchai YC6M series Heavy-Duty engine bench tests. An effective reduction of soot emission was observed with increased methanol content in the blends. Nitrogen oxide (NOx) and soot emission control strategies were also investigated at length. At high loads, if the mass fraction of methanol in the blend is controlled less than 40%, the NOx emissions of the engine would be decreased by approximately 12% while the soot emissions decreased by approximately 95%. The results indicate that the methanol engine is feasible for non-road applications.
Technical Paper

Experimental investigation of combustion timing of HVO, RME and diesel fuel in a Euro6 car engine during transient driving cycles

2019-08-15
2019-24-0138
The current targets to decrease greenhouse gases production, to reduce fossil fuel dependency and to gain energy security and sustainability are driving demand on combustion engine fuels from renewable sources. Over last more than two decades, the effort resulted in utilization of first generation biofuels. Unfortunately, these fuels brought new dilemmas and challenges in general, such as food production competition and land use and, in case of fatty acid methyl esters for compression ignition engines, also technical challenges such as storage stability and deposit formation. The technical aspects are more pronounced as advanced technologies employed to mitigate pollutants related adverse effects are applied, mandating stringent fuel properties, while demand for fuels from renewable sources is rising. Utilization of particle filters and sensitive fuel systems are driving effort to develop compatible renewable biofuels which can be utilized at higher than current shares.
Technical Paper

A novel 1D co-simulation framework for the prediction of tailpipe emissions under different IC engine operating conditions.

2019-08-15
2019-24-0147
The prediction of the pollutants emitted by internal combustion engines during driving cycles has been a challenge since the introduction of the emission regulation legislation. During the last decade, along with the more tightening limits and increased public concern about the matter of air quality, the possibility of simulating various driving tests with cost effective computing facilities has become a key feature for modern simulation codes. Many 1D simulation tools are available on the market, offering real time models capable of achieving the simulation of any driving cycle in limited time frames. These approaches are based on the extreme simplification of the engine geometry and on the adoption of engine maps, which, for any engine operating condition, give the engine output in terms of power, or torque, and of exhaust gas composition.
Technical Paper

A Mild Hybrid SIDI Turbo Passenger Car Engine with Rankine Waste Heat Recovery

2019-08-15
2019-24-0194
In the strive for more fuel-efficient vehicles all possible measures are considered to increase the efficiency of the combustion engine. 48V mild hybrid technology is one such measure; SIDI (Spark Ignited Direct Injection) engines with Miller technology another, while recovering energy from the engine waste heat (WHR) is yet an option to increase fuel conversion efficiency. Here, for the first time, we will publish the results from an advanced engineering project at Volvo Cars including all these components. We have successfully built an ethanol based Rankine system around a 4-cylinder, 2.0 litre SIDI-engine, including 48V mild hybrid technology. The Rankine system uses the engine exhaust as heat source, while the expansion of the ethanol steam occurs in an axial piston expander coupled both electrically to the hybrid system and mechanically to the engine crankshaft.
Technical Paper

CFD Investigation of the Effects of Gas’ Methane Number on the Performance of a Heavy-Duty Natural-Gas Spark-Ignition Engine

2019-08-15
2019-24-0008
Natural gas (NG) is an alternative fuel for spark-ignition engines. In addition to its cleaner combustion, recent breakthroughs in drilling technologies increased its availability and lowered its cost. NG consists of mostly methane, but it also contains heavier hydrocarbons and inert diluents, the levels of which vary substantially with geographical source, time of year, and treatments applied during production or transportation. To investigate the effects of NG composition on engine performance and emissions, a 3D CFD model of a heavy-duty diesel engine retrofitted to spark ignition operations simulated engine operation under lean-combustion, low-speed, and medium load conditions. To eliminate the effect of different gas energy density, three NG blends of similar lower heating value but different H/C ratio have been investigated at fixed spark timing.
Technical Paper

Numerical Investigation of Multiple-Injection Strategies of Methanol in a DICI HD Optical Engine

2019-08-15
2019-24-0007
Methanol fuel is a genuine candidate on the alternative fuel market for internal combustion engines within heavy-duty transportation sector. The thermo-physical properties of methanol allow to achieve high thermodynamic efficiency and low emission levels with a good margin below the EURO VI standard using compression ignition (CI) engines with advanced injection strategies. However, due to a low stoichiometric air/fuel ratio and a high latent heat of vaporization there are two challenges that can be mentioned; (a) the tendency to a high pressure rise rate due to the rapid chemical kinetic driven ignition process and, (b) the required high inlet temperature to initiate compression ignition event. These challenges can be tackled for instance by employing multiple-injection strategies, which reduces both the maximal pressure rise rate and the demand on the high inlet temperature.
Technical Paper

Heavy-Duty Compression-Ignition Engines Retrofitted to Spark-Ignition Operation Fueled with Natural Gas

2019-08-15
2019-24-0030
Natural gas is a promising alternative gaseous fuel due to its availability, economic, and environmental benefits. A solution to increase its use in the heavy-duty transportation sector is to convert existing heavy-duty compression ignition engines to spark-ignition operation by replacing the fuel injector with a spark plug and injecting the natural gas inside the intake manifold. The use of numerical simulations to design and optimize the natural gas combustion in such retrofitted engines can benefit both engine efficiency and emission. However, experimental data of natural gas combustion inside a bowl-in-piston chamber is limited. Consequently, the goal of this study was to provide high-quality experimental data from such a converted engine fueled with methane and operated at steady-state conditions, exploring variations in spark timing, engine speed and equivalence ratio.
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