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Journal Article

Impact of Fuel Properties on Diesel Low Temperature Combustion

2011-04-12
2011-01-0329
Extensive empirical work indicates that exhaust gas recirculation (EGR) is effective to lower the flame temperature and thus the oxides of nitrogen (NOx) production in-cylinder in diesel engines. Soot emissions are reduced in-cylinder by improved fuel/air mixing. As engine load increases, higher levels of intake boost and fuel injection pressure are required to suppress soot production. The high EGR and improved fuel/air mixing is then critical to enable low temperature combustion (LTC) processes. The paper explores the properties of the Fuels for Advanced Combustion Engines (FACE) Diesel, which are statistically designed to examine fuel effects, on a 0.75L single cylinder engine across the full range of load, spanning up to 15 bar IMEP. The lower cetane number (CN) of the diesel fuel improved the mixing process by prolonging the ignition delay and the mixing duration leading to substantial reduction of soot at low to medium loads, improving the trade-off between NOx and soot.
Technical Paper

Low Temperature Combustion Strategies for Compression Ignition Engines: Operability limits and Challenges

2013-04-08
2013-01-0283
Low temperature combustion (LTC) strategies such as homogeneous charge compression ignition (HCCI), smokeless rich combustion, and reactivity controlled compression ignition (RCCI) provide for cleaner combustion with ultra-low NOx and soot emissions from compression-ignition engines. However, these strategies vary significantly in their implementation requirements, combustion characteristics, operability limits as well as sensitivity to boundary conditions such as exhaust gas recirculation (EGR) and intake temperature. In this work, a detailed analysis of the aforementioned LTC strategies has been carried out on a high-compression ratio, single-cylinder diesel engine. The effects of intake boost, EGR quantity/temperature, engine speed, injection scheduling and injection pressure on the operability limits have been empirically determined and correlated with the combustion stability and performance metrics.
Technical Paper

The Impact of Intake Dilution and Combustion Phasing on the Combustion Stability of a Diesel Engine

2014-04-01
2014-01-1294
Conventionally, the diesel fuel ignites spontaneously following the injection event. The combustion and injection often overlap with a very short ignition delay. Diesel engines therefore offer superior combustion stability characterized by the low cycle-to-cycle variations. However, the enforcement of the stringent emission regulations necessitates the implementation of innovative diesel combustion concepts such as the low temperature combustion (LTC) to achieve ultra-low engine-out pollutants. In stark contrast to the conventional diesel combustion, the enabling of LTC requires enhanced air fuel mixing and hence a longer ignition delay is desired. Such a decoupling of the combustion events from the fuel injection can potentially cause ignition discrepancy and ultimately lead to combustion cyclic variations.
Technical Paper

Clean Combustion in a Diesel Engine Using Direct Injection of Neat n-Butanol

2014-04-01
2014-01-1298
The study investigated the characteristics of the combustion, the emissions and the thermal efficiency of a direct injection diesel engine fuelled with neat n-butanol. Engine tests were conducted on a single cylinder four-stroke direct injection diesel engine. The engine ran at 6.5 bar IMEP and 1500 rpm engine speed. The intake pressure was boosted to 1.0 bar (gauge), and the injection pressure was controlled at 60 or 90 MPa. The injection timing and the exhaust gas recirculation (EGR) rate were adjusted to investigate the engine performance. The effect of the engine load on the engine performance was also investigated. The test results showed that the n-butanol fuel had significantly longer ignition delay than that of diesel fuel. n-Butanol generally led to a rapid heat release pattern in a short period, which resulted in an excessively high pressure rise rate. The pressure rise rate could be moderated by retarding the injection timing and lowering the injection pressure.
Technical Paper

Computational Study of Reactivity Controlled Compression Ignition (RCCI) Combustion in a Heavy-Duty Diesel Engine Using Natural Gas

2014-04-01
2014-01-1321
Reactivity controlled compression ignition (RCCI) combustion employs two fuels with a large difference in auto-ignition properties that are injected at different times to generate a spatial gradient of fuel-air mixtures and reactivity. Researchers have shown that RCCI offers improved fuel efficiency and lower NOx and Soot exhaust emissions when compared to conventional diesel diffusion combustion. The majority of previous research work has been focused on premixed gasoline or ethanol for the low reactivity fuel and diesel for the high reactivity fuel. The increased availability of natural gas (NG) in the U.S. has renewed interest in the application of compressed natural gas (CNG) to heavy-duty (HD) diesel engines in order to realize fuel cost savings and reduce pollutant emissions, while increasing fuel economy. Thus, RCCI using CNG and diesel fuel warrants consideration.
Journal Article

Fleet Vehicle Idling - Are Supplemental Hybrid Idling Reduction Systems the Answer?

2014-01-15
2013-01-9095
Environmental concerns and rising fuel costs are driving Ontario's municipalities and fleet operators to consider alternative vehicle technologies. Elevated fuel consumption and air emissions are attributed to the unique operations of fleet vehicles and in particular, during idling. While drivers of passenger vehicles may have the option of simply not idling, fleet and emergency vehicle operators, may need to keep the vehicle operating to supply power to critical onboard equipment. These demands may be exacerbated during seasonal, temperature extremes. However, prolonged idling can impose significant environmental and economic burdens. Hybrid vehicles have yet to be utilized widely by Ontario's fleets, but there are other approaches to reduce emissions, including alternative “green” technologies to operate in-vehicle equipment and maintain fleet vehicle capabilities instead of idling.
Journal Article

Transient Build-up and Effectiveness of Diesel Exhaust Gas Recirculation

2014-04-01
2014-01-1092
Modern diesel engines employ a multitude of strategies for oxides of nitrogen (NOx) emission abatement, with exhaust gas recirculation (EGR) being one of the most effective technique. The need for a precise control on the intake charge dilution (as a result of EGR) is paramount since small fluctuations in the intake charge dilution at high EGR rates may cause larger than acceptable spikes in NOx/soot emissions or deterioration in the combustion efficiency, especially at low to mid-engine loads. The control problem becomes more pronounced during transient engine operation; currently the trend is to momentarily close the EGR valve during tip-in or tip-out events. Therefore, there is a need to understand the transient EGR behaviour and its impact on the intake charge development especially under unstable combustion regimes such as low temperature combustion.
Technical Paper

A Neural Network Approach for Predicting Collision Severity

2014-04-01
2014-01-0569
The development of a collision severity model can serve as an important tool in understanding the requirements for devising countermeasures to improve occupant safety and traffic safety. Collision type, weather conditions, and driver intoxication are some of the factors that may influence motor vehicle collisions. The objective of this study is to use artificial neural networks (ANNs) to identify the major determinants or contributors to fatal collisions based on various driver, vehicle, and environment characteristics obtained from collision data from Transport Canada. The developed model will have the capability to predict similar collision outcomes based on the variables analyzed in this study. A multilayer perceptron (MLP) neural network model with feed-forward back-propagation architecture is used to develop a generalized model for predicting collision severity. The model output, collision severity, is divided into three categories - fatal, injury, and property damage only.
Technical Paper

A Reconfigurable Algorithm for Identifying and Validating Functional Workspace of Industrial Manipulators

2014-04-01
2014-01-0734
Industrial robotic arms and manipulators are systems that offer technological advances in automation, production, and logistical processes. Therefore, it is vital to understand and analyze the reachability and dexterity of such manipulators. This paper presents a reconfigurable algorithm for evaluation and 3D visual representation of the total workspace and singularity space of two and three degrees of freedom open-ended kinematic chains. A manipulator's performance is greatly depreciated at or near singular regions which may occur as subset(s) in its complete workspace. It is therefore crucial to understand the functional workspace of a manipulator for an enhanced performance in an industrial setting. The implementation of this algorithm requires two inputs namely; the joint type(s), rotational (R) or translational (T), and the Denavit-Hartenberg (D-H) parameters of the manipulator.
Journal Article

A Methodology for Investigating and Modelling Laser Clad Bead Geometry and Process Parameter Relationships

2014-04-01
2014-01-0737
Laser cladding is a method of material deposition through which a powdered or wire feedstock material is melted and consolidated by use of a laser to coat part of a substrate. Determining the parameters to fabricate the desired clad bead geometry for various configurations is problematic as it involves a significant investment of raw materials and time resources, and is challenging to develop a predictive model. The goal of this research is to develop an experimental methodology that minimizes the amount of data to be collected, and to develop a predictive model that is accurate, adaptable, and expandable. To develop the predictive model of the clad bead geometry, an integrated five-step approach is presented. From the experimental data, an artificial neural network model is developed along with multiple regression equations.
Technical Paper

Effect of Surface Roughness and Sliding Velocity on Tribological Properties of an Oxide-Coated Aluminum Alloy

2014-04-01
2014-01-0957
Aluminum engines have been successfully used to replace heavy gray cast engines to lighten the car's weight and reduce the fuel consumption. To overcome the aluminum alloys' poor wear resistance, cast iron liners and thermal spraying coatings were used as cylinder bore materials for wear protection. A plasma electrolytic oxidation (PEO) technique had also been proposed to produce an oxide coating on aluminum cylinder bore. The oxide coating can have a low coefficient of friction (COF) and minimum wear shown in the lab tests. To conserve more fuel, the stopping and restarting system was introduced when the vehicle was forced to stop immediately for a short time. When the engine was forced to stop and restart, the reciprocating speed of the piston was very slow, and the friction between the piston and the cylinder was high. In this research, a pin-on-disc tribometer was used to investigate tribological behavior of the oxide coating on an aluminum alloy.
Technical Paper

Active Suspension Handling Simulation using Cosimulation

2010-12-01
2010-01-1582
In this study the capabilities of a semi-active suspension and an active roll suspension are evaluated for comparison with a passive suspension. The vehicle used is a utility truck modeled as a multi-body system in ADAMS/Car while the ECU (electronic control unit) is built in Matlab/Simulink. Cosimulation is used in linking the vehicle model with the controller by exchanging the input and output values of each sub-system with one another. For the simulation models considered, results indicate that for a fish-hook cornering maneuver the semi-active suspension is limited in increasing vehicle performance while the active roll suspension significantly improves it. Further analysis is needed to confirm these findings.
Technical Paper

Power Management Methodologies for Fuel Cell-Battery Hybrid Vehicles

2010-04-12
2010-01-0849
The implementation of fuel cell-battery hybrid vehicles requires a supervisory control strategy that manages the power distribution between the fuel cell and the energy storage device (i.e., battery). Several advanced control methods have already been developed and published in literature. However, most control methods have been developed for different vehicle types and using different mathematical models. The performance of these power management methods have not been directly compared for the same application. This study aims at obtaining direct analytical comparisons, which will provide useful insight in selecting a power management method for fuel cell-battery hybrid vehicles.
Technical Paper

Dynamic Stability Analysis of Coupled Vehicles for General and Military Applications

2010-04-12
2010-01-0638
The paper describes a study conducted by the University of Windsor Vehicle Dynamics and Control Research Group into the stability of coupled vehicles, e.g., truck-trailer combinations. Several instabilities associated with truck-trailer combinations have been well documented, and have been predicted using mathematical models. Despite having relatively low complexity the classic truck-trailer model, a simple two body, three degree of freedom, linear model has been used extensively in coupled vehicle stability analyses. The aim of the presented work was to extend the conventional coupled vehicle analysis with a set of more elaborate mathematical models evaluating various vehicle configurations. Using in-house multibody dynamics software the linearized equations of motion of three dimensional models were automatically generated for various coupled vehicle configurations with general and military applications. Stability analyses were conducted over a range of expected operating speeds.
Technical Paper

Engine Fault Detection Using Vibration Signal Reconstruction in the Crank-Angle Domain

2011-05-17
2011-01-1660
Advanced engine test methods incorporate several different sensing and signal processing techniques for identifying and locating manufacturing or assembly defects of an engine. A successful engine test method therefore, requires advanced signal processing techniques. This paper introduces a novel signal processing technique to successfully detect a faulty internal combustion engine in a quantitative manner. Accelerometers are mounted on the cylinder head and lug surfaces while vibration signals are recorded during engine operation. Using the engine's cam angular position, the vibration signals are transformed from the time domain to the crank-angle domain. At the heart of the transformation lies interpolation. In this paper, linear, cubic spline and sinc interpolation methods are demonstrated for reconstructing vibration signals in the crank-angle domain.
Technical Paper

In-vehicle Speech Intelligibility for the Hearing Impaired Using Speech Intelligibility Index

2011-05-17
2011-01-1681
Individuals with hearing impairments often report hearing difficulties within the driving environment. This is an ever growing issue given the increasing population of senior aged drivers. In this study, Speech Intelligibility Index (SII) is used to predict in-vehicle speech intelligibility of individuals having common hearing impairments. The effect of hearing threshold levels obtained from audiograms and the impact of vehicle background noise measured for various vehicle operating conditions, road surface types and talker and listener configurations are investigated. This is done by using measured and user-defined speech spectra as described by ANSI S3.5-1997 (Methods for Calculation of the Speech Intelligibility Index). The results demonstrate poor speech intelligibility for most situations considered and provide evidence for the need to improve automotive interior sound quality in terms of speech intelligibility for hearing impaired drivers including aged drivers.
Journal Article

An Empirical Study to Extend Engine Load in Diesel Low Temperature Combustion

2011-08-30
2011-01-1814
In this work, engine tests were performed to realize EGR-enabled LTC on a single-cylinder common-rail diesel engine with three different compression ratios (17.5, 15 and 13:1). The engine performance was first investigated at 17.5:1 compression ratio to provide baseline results, against which all further testing was referenced. The intake boost and injection pressure were progressively increased to ascertain the limiting load conditions for the compression ratio. To extend the engine load range, the compression ratio was then lowered and EGR sweep tests were again carried out. The strength and homogeneity of the cylinder charge were enhanced by using intake boost up to 3 bar absolute and injection pressure up to 180 MPa. The combustion phasing was locked in a narrow crank angle window (5~10° ATDC), during all the tests.
Technical Paper

Empirical Study of Energy in Diesel Combustion Emissions with EGR Application

2011-08-30
2011-01-1817
Modern diesel engines were known for producing ultra-low levels of hydrogen and hydrocarbons. However, as emission control techniques such as exhaust gas recirculation (EGR) are implemented to meet stringent NOx standards, the resulting increase in partial-combustion products can be significant in quantity both as pollutants and sources of lost engine efficiency. In this work, a modern common-rail diesel engine was configured to investigate the EGR threshold for elevated carbon monoxide, hydrocarbon, and hydrogen emissions at fixed loads and fixed heat-release phasing. It is noted that increase in hydrocarbons, in particular light hydrocarbons (such as methane, ethylene, and acetylene) was concurrent with ultra-low NOx emissions. Hydrogen gas can be emitted in significant quantities with the application of very high EGR. Under ultra-low NOx production conditions for medium and high load conditions, the light hydrocarbon species can account for the majority of hydrocarbon emissions.
Technical Paper

The Band Importance Function in the Evaluation of the Speech Intelligibility Index at the Speech Reception Threshold within a Simulated Driving Environment

2013-05-13
2013-01-1953
This study provides an overview of a novel method for evaluating in-vehicle speech intelligibility using the Speech Intelligibility Index (SII). The approach presented is based on a measured speech signal evaluated at the sentence Speech Reception Threshold (sSRT) in a simulated driving environment. In this context, the impact of different band importance functions in the evaluation of the SII using the Hearing in Noise Test (HINT) in a driving simulator is investigated.
Journal Article

Comparison of Austempering and Quench-and-Tempering Processes for Carburized Automotive Steels

2013-04-08
2013-01-0173
Carburized parts often see use in powertrain components for the automotive industry. These parts are commonly quenched and tempered after the carburizing process. The present study compared the austempering heat treatment to the traditional quench-and-temper process for carburized parts. Samples were produced from SAE 8620, 4320, and 8822 steels and heat treated across a range of conditions for austempering and for quench-and-tempering. Distortion was examined through the use of Navy C-Ring samples. Microstructure, hardness, and Charpy toughness were also examined. X-ray diffraction was used to compare the residual stress found in the case of the components after the quench-and-temper and the austempering heat treatments. Austempering samples showed less distortion and higher compressive residual stresses, while maintaining comparable hardness values in both case and core. Toughness measurements were also comparable between both processes.
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