Refine Your Search

Topic

Author

Affiliation

Search Results

Training / Education

Combustion and Emissions for Engineers

2019-12-09
Public awareness regarding pollutants and their adverse health effects has created an urgent need for engineers to better understand the combustion process as well as the pollutants formed as by-products of that process. To effectively contribute to emission control strategies and design and develop emission control systems and components, a good understanding of the physical and mathematical principles of the combustion process is necessary. This seminar will bring issues related to combustion and emissions "down to earth," relying less on mathematical terms and more on physical explanations and analogies.
Training / Education

Exhaust Flow Performance and Pressure Drop of Exhaust Components and Systems

2019-09-20
Designing more efficient and robust emission control components and exhaust systems results in more efficient performance, reduced backpressure and fuel penalty, and higher conversion efficiency. This course will help you to understand the motion of exhaust flow in both gasoline and diesel emission control components including flow-through and wall-flow devices such as catalytic converters, NOx adsorbers, diesel oxidation catalysts, diesel particulate filters as well as flow through the overall exhaust system.
Technical Paper

Numerical investigation of Electrostatic Spray Painting Transfer Processes for vehicle Coating

2019-09-16
2019-01-1856
In this study we examined numerically the electrostatic spray transfer processes in the rotary bell spray applicator, which is this case implemented in a full 3D representation. The algorithm implemented and developed for this simulation includes airflow, spray dynamics, tracking of paint droplets and an electrostatic modularized solver to present atomization and in-flight spray phenomena for the spray forming procedure. The algorithm is implemented using the OpenFOAM package. The shaping airflow is simulated via an unsteady 3D compressible Navier-Stokes method. Solver for particle trajectory was developed to illustrate the process of spray transport and also the interaction of airflow and particle that is solved by momentum coupling. As the numerical results in this paper indicates dominant operating parameter voltage setting, further the charge to mass ratio and air-paint flow rate deeply effect the spray shape and the transfer efficiency (TE).
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

The benefits of using Composite Bearings in Aircraft Shock Absorbers

2019-09-16
2019-01-1898
This paper will use actual examples from aircraft recently introduced into service, to describe the main advantages of changing from the currently used metallic bearings, to composite bearings. Abstract: The introduction of composite bearing in a recently introduced twin aisle aircraft has resulted in: • Weight saving, by replacing bronze bearings with plastic bearings • Lowering of the particle count in the shock absorber oil, (Reduced contamination with metal particles) leading to reduced wear on seals and bearings. Qualification testing showed that Composite Bearings are able to provide longer service life than bronze bearings.
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

Effects of In-cylinder flow structures on soot formation and oxidation in a swirl-supported light-duty diesel engine

2019-08-15
2019-24-0009
In this paper, computation fluid dynamics (CFD) simulations are performed to describe the effect of in-cylinder flow structures on the formation and oxidation of soot in a swirl-supported light-duty diesel engine. The focus of the paper is on the effect of swirl motion and injection pressure on late cycle soot oxidation. The structure of the flow at different swirl numbers is studied to investigate the effect that varying swirl number imposes on the coherent flow structures. These coherent flow structures are studied to understand the mechanism that leads to efficient soot oxidation in late cycle. Effect of varying injection pressure at different swirl numbers and the interaction between spray and swirl motions are discussed. The complexity of diesel combustion, especially when soot and other emissions are of interest, requires using a detailed chemical mechanism to have a correct estimation of temperature and species distribution.
Technical Paper

A Computationally Efficient Progress Variable Approach for In-Cylinder Combustion and Emissions Simulations

2019-08-15
2019-24-0011
The use of complex reaction schemes is accompanied by high computational cost in 3D CFD simulations but is particularly important to predict pollutant emissions in in-cylinder simulations. One solution to tackle this problem is to use tabulated chemistry. The approach presented herein combines pre-tabulated progress variable-based source terms for auto-ignition as well as soot and NOx source terms for advanced emission predictions. The method is coupled to CONVERGE v2.4 via user-coding and tested over various speed and load passenger-car Diesel engine conditions. This work includes the comparison between the combustion progress variable (CPV) model and the on-line chemistry solver in CONVERGE 2.4. Both models are also compared against experimental data by means of combustion and emission parameters. A detailed mechanism comprising 190 species, having n-decane/α-methyl-naphthalene as main fuels, is used for both on-line and tabulated chemistry simulations.
Technical Paper

Computational Chemistry Consortium: surrogate fuel mechanism development, pollutants submechanisms and components library.

2019-08-15
2019-24-0020
The Computational Chemistry Consortium (C3) is dedicated to leading the advancement of combustion and emissions modeling in internal combustion engines. The C3 cluster combines the expertise of different groups involved in combustion research aiming to refine existing chemistry models and to develop more efficient tools for the generation of surrogate and multi-fuel mechanisms, and suitable mechanisms for CFD applications. In addition to the development of more accurate kinetic models for different components of interest in real fuels’ surrogates and for pollutants formation (NOx, PAHs, soot), the core activity of C3 is to develop a tool capable of merging high fidelity kinetics from different sources (i.e. different partners), resulting in a high-fidelity model for a specific application.
Technical Paper

Impact of cooled EGR on performance and emissions of a turbocharged Spark-Ignition engine under low-full load conditions

2019-08-15
2019-24-0021
The stringent worldwide exhaust emission legislations for CO2 and pollutants require significant efforts to increase both the combustion efficiency and the emission quality of internal combustion engines. With this aim, several solutions are continuously produced to improve the combustion efficiency of spark ignition engines. Among the various solutions, EGR represents a well-established technology to improve the gasoline engine performance and the nitrogen-oxides emissions. This work presents the results of an experimental investigation on the effects of the EGR technique on combustion evolution, knock tendency, performance and emissions of a small–size turbocharged PFI SI engine, equipped with an external cooled EGR system. Measurements are carried out at different engine speeds, on a wide range of loads and EGR levels. The standard engine calibration is applied at the reference test conditions.
Technical Paper

Experimental and numerical investigation of the maximum pressure rise rate for an LTC concept in a single cylinder CI engine

2019-08-15
2019-24-0023
In the foreseeable future, the transportation sector will continue to rely on internal combustion engines. Therefore, reduction of engine-out emissions and increase in engine efficiency are important goals to meet future legislative regulations and restricted fuel resources. One viable option, which provides lower peak temperatures and increased mixture homogeneity and thus simultaneously reduces nitric oxide as well as soot, is a low-temperature combustion (LTC) concept. However, this might result in an increase of unburnt hydrocarbon, carbon monoxide, and combustion noise due to early combustion phasing and lower engine efficiency. Various studies show that these drawbacks can be compensated by advanced injection strategies, e.g. by employing multiple injections. The aim of this work is to identify the optimum injection strategy, which enables a wide range of engine operating points in LTC mode with reduced engine-out emissions.
Technical Paper

Potential to reduce nano-particle emission in SG-DISI engine with normal butane.

2019-08-15
2019-24-0022
Under lean stratified combustion, differed from the stoichiometric homogeneous charge combustion, flame could propagate through extremely rich air-fuel mixture. The rich mixture causes considerable amount of particulate matter, but, due to large effect of efficiency improvement, the attractive point is on fuel economy compare to homogeneous charge SI combustion. The easiest way to reduce particulate matter is changing fuel to gaseous hydrocarbon, to minimize evaporating and mixing period. In this study, to reduce the particulate emission and to develop the way to mitigation of emission, the emission data of particulate under low and medium-low load conditions from normal butane fueled research engine are dealt to optimize combustion strategies, with respect to injection and ignition. Especially, particulate number density were collected in the research engine, and the causes of particulate formation were speculated with visualized combustion data.
Technical Paper

On the HCCI octane boosting effects of γ-Valerolactone

2019-08-15
2019-24-0026
Transportation sector is almost entirely powered by internal combustion engines (ICEs) burning petroleum-based liquid fuels. This makes the transportation sector the main culprit of global warming due to the large quantity of CO2 emission from burning these petroleum-based fuels. Over the last few decades, there are growing concerns over global warming and diminishing petroleum reserves. Such concerns have led to concentrated efforts directed at a paradigm shift from conventional fuels to renewable alternatives which can promote cleaner combustion. Therefore, future research directions should orient towards exploring new fuels suitable for future ICEs to achieve better engine efficiency and significantly less harmful emissions. One way to achieve these objectives is to focus on improving the combustion technology by developing new fuel-engine systems. Consequently, scientists and engineers are showing growing interest towards non-petroleum-based fuels coming from renewable resources.
Technical Paper

Optimization of Multi Stage Direct Injection-PSCCI Engines

2019-08-15
2019-24-0029
The more stringent regulations on emissions induce the automotive companies to develop new solutions for engine design, including the use of advanced combustion strategies and the employment of mixture of fuels with different thermochemical properties. The HCCI combustion coupled with the partial direct injection of the charge, in order to control the performance and emissions and to extend the operating range, is a promising technique. In this work an in-house developed multi-dimensional CFD software package was used to analyse the behaviour of a multi stage direct injection (DI)-partially stratified charge compression ignition engine fueled with PRF. A skeletal kinetic mechanism for PRF oxidation was employed, with a dynamic adaptive chemistry technique to reduce the computational cost and a model based on the partially stirred reactor model to couple turbulence and chemistry.
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.
Technical Paper

Effects of Droplet Behaviors on Fuel Adhesion of Flat Wall Impinging Spray injected by a DISI Injector

2019-08-15
2019-24-0034
Owing to the short impingement distance and high injection pressure, it is difficult to avoid the fuel spray impingement on the combustion cylinder wall and piston head in Direct Injection Spark Ignition (DISI) engine, which is a possible source of hydrocarbons and soot emission. For better understanding of the mechanisms behind the spray-wall impingement, the fuel spray and adhesion on a flat wall using a mini-sac injector with a single hole was examined. The microscopic characteristics of impinging spray were investigated through Particle Image Analysis (PIA). The droplet size and velocity were compared before and after impingement. The adhered fuel on the wall was measured by Refractive Index Match-ing (RIM). Time-resolved fuel adhesion evolution as well as adhesion mass, area, and thickness were discussed. Moreover, the relationships between droplets behaviors and fuel adhesion on the wall were discussed.
Technical Paper

Experimental High Temperature Analysis of a Low-Pressure Diesel Spray for DPF Regeneration

2019-08-15
2019-24-0035
In the current automotive scenario, particulate filter technology is mandatory in order to attain emission limits in terms of particulate matter for Diesel engines. Despite DPF is often considered a mature technology, significant issues can derive from the use of the engine fuel injectors to introduce in the exhaust pipe the fuel needed to light on the particulate matter in the filter during its regeneration, primarily the lubricant oil dilution with fuel a consequence of significant spray impact on the cylinder liner. As an alternative, the fuel required to start regeneration can be introduced in the exhaust pipe by an auxiliary low pressure injector spraying in the hot exhaust gas stream. In this conditions, the spray evolution and its possible interaction with the surrounding gas stream are relevant in order to better identify the overall layout of the system, so to have the fuel vaporized at the DPF inlet section.
Technical Paper

Gasoline Spray_Models_Calibration_Under_Diesel_Engine_Like_Conditions

2019-08-15
2019-24-0032
Atomization of liquid fuel jets is critical to the performance of Internal Combustion (IC) engine, as it plays a key role in affecting mixture formation, combustion efficiency and soot emissions. In the Gasoline Compression Ignition (GCI) engine investigation, the experimental measurements on the gasoline injection into diesel engine like condition, shows the difficulty in matching the liquid penetration length when the diesel spray model is used. Additional tests performed at lower ambient densities, seen in early injection, revealed a lot of information on liquid jet dynamics behavior. It requires a lot of model calibration effort in matching the measured liquid and vapor penetration length under different ambient pressure conditions. It is found that using droplet Sauter Mean Diameter distribution model shows better match with experiment at low density condition, whereas the KH-ACT breakup model correlates well with measurement at high density condition.
Technical Paper

Combustion and Emission Characteristics of a Compression Ignition Engine Fuelled with Diesel-LPG Blends

2019-08-15
2019-24-0038
Alternative fuels have recently attracted considerable attention due to their potential role in improving ambient air quality and mitigating global warming. Recent research has applied a variety of alternative fuels in an attempt to satisfy these requirements. Clearly, the alternative fuels industry needs to build confidence from fuels that perform well without adding considerable cost to the consumer. Although not a renewable fuel, liquefied petroleum gas (LPG) is a low-cost alternative fuel that might meet these needs; albeit temporarily. LPG is well known as an alternative fuel for spark ignition (SI) engines and, more recently, LPG systems have also been introduced to compression ignition (CI) engines. In this framework, to investigate the practical application and potential of this concept, diesel was blended with LPG, in different ratios (20-35% w/w). For this purpose, a single-cylinder test rig was properly adapted and, a standard common rail fuel injection system was employed.
Technical Paper

Emissions Optimization Potential of a Diesel Engine Running on HVO: A Combined Experimental and Simulation Investigation

2019-08-15
2019-24-0039
The present work investigates some recalibration possibilities of a 1.4l common rail turbo-charged diesel engine for the optimal operation in terms of emissions and fuel consumption (FC) with pure Hydrotreated Vegetable Oil (HVO). Initially, steady-state experimental data with nominal engine settings revealed HVO benefits as a drop-in fuel. Under these conditions, pure HVO is associated with lower engine out PM (up to 75%) and CO2 (up to 10%) emissions, and lower mass-based FC (up to 9%), while NOx are similar or slightly higher to diesel fuel. At the next step, a combustion model was developed for the particular engine targeting to identify the optimal IT (Injection Timing) and EGR settings for further emissions (PM, NOx and CO2) and FC reduction with pure HVO. For this purpose, four re-adjusted IT and EGR maps were developed with both conventional diesel and HVO.
X