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Viewing 121 to 150 of 24423
2017-03-28
Technical Paper
2017-01-0511
Tianhao Yang, Lianhao Yin, Gabriel Ingesson, Per Tunestal, Rolf Johansson, Wuqiang Long
In this paper, a control-oriented soot model was developed for the use of soot real-time prediction and combustion condition optimization. As a promising combustion concept, Partially Premixed Combustion (PPC) achieves high engine efficiency, and reduces soot and NOx simultaneously. However, soot emission was found to be significantly increased with high load, high EGR and split injection. In order to investigate factors that influence soot emissions on a multi-cylinder heavy duty gasoline PPC engine, sensitivity analysis upon EGR rate, injection profile, intake pressure and intake temperature were mainly studied. An empirical model was modified based on the original Hiroyasu model according to the sensitivity results. By introducing pilot ratio as a compensation factor, This model can be used to predict soot emission under double injection. 7 model parameters were identified using experiment data under a few representative operating points.
2017-03-28
Journal Article
2017-01-1273
Qiang Dai, Jarod C. Kelly, Amgad Elgowainy
Vehicle lightweighting has been a focus of the automotive industry, as car manufacturers seek to comply with the corporate average fuel economy (CAFE) and the greenhouse gas (GHG) standards for MY 2017-2025 vehicles. However, when developing a lightweight vehicle design, the automotive industry typically targets maximum vehicle weight reduction at minimal capital cost. In this paper we consider the environmental impacts incurred by some of the lightweighting technology options. The materials generally used for vehicle lightweighting include high-strength steel (HSS), aluminum, magnesium and carbon fiber reinforced plastic (CFRP). Except for HSS, the production of these light materials is more GHG-intensive (on a kg-to-kg basis) compared with the conventional automotive materials they substitute. Lightweighting with these materials, therefore, may partially offset the GHG emission reductions achieved through improved fuel economy.
2017-03-28
Journal Article
2017-01-0920
Jean P. Roy, Ahmed Ghoniem, Robert Panora, Joseph Gehret, Bruce Falls, David Wallace, Daniel Ott
All vehicles sold today are required to meet emissions standards based on specific driving cycles. A dual stage catalyst system, with exhaust temperature control, can provide a robust solution to meet challenging modes of operation such as rapid acceleration and other heavy duty transients. The Ultera technology, developed and successfully implemented on stationary natural gas CHP engines, introduces a second stage oxidation catalyst downstream of a three-way catalyst. Air is injected between the two catalyst stages to provide oxygen required for the second stage reaction that removes additional CO and NMOG. Critical to the process is to avoid the reformation of NOx, a common consequence with similar air injection concepts that have been tried in the past. This is achieved by cooling the exhaust gas prior to the second stage to a temperature range in which CO and NMOG oxidation is extremely effective while no new NOx is created.
2017-03-28
Technical Paper
2017-01-0599
Yichao Guo
Misfire is generally defined as be no or partial combustion during the power stroke of internal combustion engine. Because a misfired engine will dramatically increase the exhaust emission and potentially cause permanent damage to the catalytic converters, California Air Resources Board (CARB), as well as most of other countries’ on-board diagnostic regulations mandates the detection of misfire. Currently almost all the OEMs utilize crankshaft position sensors as the main input to their misfire detection algorithm. The detailed detection approaches vary among different manufacturers. For example, some chooses the crankshaft angular velocity calculated from the raw output of the crankshaft position sensor as the measurement to distinguish misfires from normal firing events, while others use crankshaft angular acceleration or the associated torque index derived from the crankshaft position sensor readings as the measurement of misfire detection.
2017-03-28
Journal Article
2017-01-1316
Dhaval Vaishnav, Mohsen Ehteshami, Vylace Collins, Syed Ali, Alan Gregory, Matthew Werner
A jet pump, or an ejector, functions on the ability of a high velocity jet to entrain surrounding stationary fluid. When a high pressure flow from a primary inlet passes through a nozzle, it creates low pressure zone due to venturi effect. The low pressure zone allows flow entrainment from a secondary inlet. For a given pressure at primary inlet, it is desired to entrain maximum flow from secondary inlet. Jet pumps have been used in automobiles for a variety of applications such as: transferring liquid fuel between two halves of the saddle type fuel tank and entraining fresh coolant in the cooling circuit. Recently, jet pumps have been used in evaporative emission control system to remove gaseous hydrocarbons stored in carbon canister and supply it to intake manifold (canister purging). Naturally aspirated engines use vacuum pressure inside the intake manifold for canister purging. However, turbocharged engines operate at or above atmospheric pressure.
2017-03-28
Journal Article
2017-01-1511
Anton Kabanovs, Graham Hodgson, Andrew Garmory, Martin Passmore, Adrian Gaylard
The motivation for this paper is to consider the effect of rear end geometry on rear soiling using a representative generic SUV body. In particular the effect of varying the top slant angle is considered using both experiment and Computational Fluid Dynamics (CFD). Previous work has shown that slant angle has a significant effect on wake shape and drag and here we extend this to investigate the effect on rear soiling. It is hoped that this work can provide an insight into the likely effect of such geometry changes on the soiling of similarly shaped road vehicles. To increase the generality of results, and to allow comparison with previously obtained aerodynamic data, a 25% scale generic SUV model is used in the Loughborough University Large Wind Tunnel. UV doped water is sprayed from a position located at the bottom of the left rear tire to simulate the creation of spray from this tire.
2017-03-28
Journal Article
2017-01-1327
Prashant Khapane, Vivek Chavan, Uday Ganeshwade
Physical testing of a vehicle wading through water is performed to gauge the capability of a vehicle to traverse through shallow to deep levels of water; wherein various vehicle performance parameters are observed, recorded and analysed. Jaguar Land Rover (JLR) has instigated and established a comprehensive CAE test procedure for the assessing the same, which makes use of overset mesh (in a CFD environment) for a non-traditional approach to vehicle motion. An extended simulation methodology, making use of the passive scalar model has been established to understand water impingement and splashing in a greater detail, which are the two critical performance parameters during vehicle wading. A passive scalar acts as a pseudo catalyst in the target fluid phase of the multiphase CFD simulation.
2017-03-28
Journal Article
2017-01-1276
Aditi Moorthy, Robert De Kleine, Gregory Keoleian, Jeremy Good, Geoff Lewis
The problem of accessibility to public transit is a well-documented problem in transportation theory and network literature known as the “Last Mile” problem. A lack of first and last mile specific transit services impairs access to public transit causing commuters to opt for private modes of transit over public modes of transit. This paper analyzes the implications of a shared autonomous vehicle (AV) taxi system providing last mile specific transit services in terms of environmental, cost, and performance metrics. Conventional public transit options along with a hypothetical last-mile shared autonomous vehicle (SAV) system are analyzed for transit between Ann Arbor and Detroit Wayne County Airport for life cycle energy, emissions, total travel time, and travel costs. In the case study, energy savings from using public transit options with AV last mile service were as high as 39% when compared to a personal vehicle (parking) option.
2017-03-28
Journal Article
2017-01-1319
Christoph Huber, Bernhard Weigand, Heinrich Reister, Thomas Binner
Abstract A simulation approach to predict the amount of snow which is penetrating into the air filter of the vehicle’s engine is important for the automotive industry. The objective of our work was to predict the snow ingress based on an Eulerian/Lagrangian approach within a commercial CFD-software and to compare the simulation results to measurements in order to confirm our simulation approach. An additional objective was to use the simulation approach to improve the air intake system of an automobile. The measurements were performed on two test sites. On the one hand we made measurements on a natural test area in Sweden to reproduce real driving scenarios and thereby confirm our simulation approach. On the other hand the simulation results of the improved air intake system were compared to measurements, which were carried out in a climatic wind tunnel in Stuttgart.
2017-03-28
Technical Paper
2017-01-1318
Prashant Khapane, Suresh Bhosale
Abstract Robustness to sand dune impact is one of the key requirements for Jaguar Land Rover products. Historically off road vehicles were built on a ladder sub frame; and the steel cross beam at the front provided robust protection for the cooling pack. With the move to monocoque construction, the cooling pack became vulnerable to low speed grounding damage. Unfortunately this vulnerability is not confirmed until later in the program when fully representative vehicles are available, which results in late engineering changes that are expensive, time consuming and stressful. Like all late changes it is rarely optimised for cost and weight. With no historic literature or procedure available, the challenge was to model the physics of sand media and also solve the complex multi-physics problem of impact of the whole vehicle with the sand dune.
2017-03-28
Journal Article
2017-01-1278
Keisuke Isomura
Abstract In the automobile industry, interest in the prevention of global warming has always been high. The development of eco cars (HV, EV etc.), aimed at reducing CO2 emissions during operation, has been progressing. In the announcement of its "Toyota Environmental Challenge 2050", Toyota declared its commitment to creating a future in which people, cars, and nature coexist in harmony. In this declaration, Toyota committed to reducing CO2 emissions not only during operation but also over the entire life cycle of vehicles, and to using resources effectively based on a 4 R’s approach (refuse, reduce, reuse, and recycle). Although eco cars decrease CO2 emissions during operation, most of them increase CO2 emissions during manufacturing. For example, the rare-earths (Nd, Dy etc.) used in the magnets of driving motors are extracted through processes that produce a significant amount of CO2 emissions.
2017-03-28
Journal Article
2017-01-1277
Jakobus Groenewald, Thomas Grandjean, James Marco, Widanalage Widanage
Abstract Increasingly international academic and industrial communities desire to better understand, implement and improve the sustainability of vehicles that contain embedded electrochemical energy storage. Underpinning a number of studies that evaluate different circular economy strategies for the electric vehicle (EV) battery system are implicit assumptions about the retained capacity or State-of-Health (SoH) of the battery. International standards and best-practice guides exist that address the performance evaluation of both EV and HEV battery systems. However, a common theme in performance testing is that the test duration can be excessive and last for a number of hours. The aim of this research is to assess whether energy capacity and internal resistance measurements of Li-ion based modules can be optimized, reducing the test duration to a value that may facilitate further End-of-Life (EoL) options.
2017-03-28
Journal Article
2017-01-1328
Yoshiteru Tanaka, Jun Yamamura, Atsushi Murakawa, Hiroshi Tanaka, Tsuyoshi Yasuki
Abstract When vehicles run on the flooded road, water enters to the engine compartment and sometimes reaches the position of the air intake duct and electrical parts and causes the reliability problems. Numerical simulation is an effective tool for this phenomenon because it can not only evaluate the water level before experiment but also identify the intrusion route. Recently, the gap around the engine cooling modules tends to become smaller and the undercover tends to become bigger than before in order to enhance the vehicle performance (e.g., aerodynamics, exterior noise). Leakage tightness around the engine compartment becomes higher and causes an increase of the buoyancy force from the water. Therefore the vehicle attitude change is causing a greater impact on the water level. This paper describes the development of a water level prediction method in engine compartment while running on the flooded road by using the coupled multibody and fluid dynamics.
2017-03-28
Technical Paper
2017-01-1320
Yucheng Liu
Abstract A cost effective, portable particulate management system was developed, prototyped, and evaluated for further application and commercialization, which could remove and dispose particulate matter suspended in air efficiently and safely. A prototype of the present system was built for experimental assessment and validation. The experimental data showed that the developed particulate management system can effectively clean the air by capturing the particles inside it. Effects of viscosity of filter medium on the performance of the developed system were also discussed. The present system is very flexible, whose size and shape can be scaled and changed to be fit for different applications. Its manufacturing cost is less than $10. Based on the experimental validation results, it was found that the present system can be further developed, commercialized, and applied for a variety of industries.
2017-03-28
Journal Article
2017-01-1322
Kunihiko Yoshitake, Hiroyuki Tateyama, Atsushi Ogawa
Abstract Vehicles are required durability in various environments all over the world. Especially water resistance on flooded roads is one of the important issues. To solve this kind of problem, a CFD technology was established in order to predict the water resistance performance of the vehicle at the early development stage. By comparison with vehicle tests on flooded roads, it is clarified the following key factors are required for accurate prediction; the vehicle velocity change, the vehicle height change and the air intake flow rate. Moreover, these three key factors should be appropriately determined from vehicle and engine specification to predict water intrusion for flooded roads at the early stage of development. In this paper, a methodology which determines appropriate analysis conditions mentioned above for flooding simulation from vehicle and engine specification is described. The methodology enables us to determine whether the vehicle provides sufficient waterproofness.
2017-03-28
Technical Paper
2017-01-1400
Keyu Qian, Gangfeng Tan, Renjie Zhou, Binyu Mei, Wanyang XIA
Downhill mountain road is the accident prone section because of its complexity and variety. Drivers rely more on driving experience and it is very easy to cause traffic accidents due to negligence or failure of judgment. Traditional active safety systems, such as ABS, subjects to the driver's visual feedback, can’t fully guarantee the downhill driving safety in complex terrain environment. This study combines the characteristics of vehicle dynamics and geographic information, giving drivers safety speed in advance to reduce traffic accidents due to driver's miscarriage of justice or brake overheating and enhance the safety of vehicles in the downhill. Firstly, establish the commercial vehicle driving model, main brake and auxiliary brake model, and study the characteristics of the driving conditions under the change of slope length and slope. Gather the real-time information of the vehicle, such as vehicle weight, speed, gear and engine speed to calculate the vehicle braking torque.
2017-03-28
Journal Article
2017-01-1543
Jonathan Jilesen, Adrian Gaylard, Jose Escobar
Abstract Vehicle rear and side body soiling has been a concern since the earliest cars. Traditionally, soiling has been seen to be less importance than vehicle aerodynamics and acoustics. However, increased reliance on sensors and cameras to assist the driver means that there are more surfaces of the vehicle that must be kept clean. Failure to take this into consideration means risking low customer satisfaction with new features. This is because they are likely to fail under normal operating conditions and require constant cleaning. This paper numerically investigates features known to have an influence on side and rear face soiling with a demonstration vehicle. These changes include rim design, diffuser strakes and diffuser sharpening. While an exhaustive investigation of these features is beyond the scope of this study, examples of each feature will be considered.
2017-03-28
Journal Article
2017-01-1639
Gerard W. Malaczynski, Gregory Roth
Abstract Onboard diagnostic regulations require performance monitoring of diesel particulate filters used in vehicle aftertreatment systems. Delphi has developed a particulate matter (PM) sensor to perform this function. The objective of this sensor is to monitor the soot (PM) concentration in the exhaust downstream of the diesel particulate filter which provides a means to calculate filter efficiency. The particulate matter sensor monitors the deposition of soot on its internal sensing element by measuring the resistance of the deposit. Correlations are established between the soot resistance and soot mass deposited on the sensing element. Currently, the sensor provides the time interval between sensor regeneration cycles, which, with the knowledge of the exhaust gas flow parameters, is correlated to the average soot concentration.
2017-03-28
Journal Article
2017-01-1552
Mehriar Dianat, Maciej Skarysz, Graham Hodgson, Andrew Garmory, Martin Passmore
Abstract The motivation for this paper is to predict the flow of water over exterior surfaces of road vehicles. We present simulations of liquid flows on solid surfaces under the influence of gravity with and without the addition of aerodynamic forces on the liquid. This is done using an implementation of a Coupled Level Set Volume of Fluid method (CLSVOF) multiphase approach implemented in the open source OpenFOAM CFD code. This is a high fidelity interface-resolving method that solves for the velocity field in both phases without restrictions on the flow regime. In the current paper the suitability of the approach to Exterior Water Management (EWM) is demonstrated using the representative test cases of a continuous liquid rivulet flowing along an inclined surface with a channel located downstream perpendicular to the oncoming flow.
2017-03-28
Technical Paper
2017-01-0591
Andreas Thomasson, Xavier Llamas, Lars Eriksson
In modern turbocharged engines the power output is strongly connected to the turbocharger speed, through the flow characteristics of the turbocharger. Turbo speed is therefore an important state for the engine operation, but it is usually not measured or controlled directly. Still the control system must ensure that the turbo speed does not exceed its maximum allowed value to prevent damaging the turbocharger. Having access to a turbo speed signal, preferably by a cheap and reliable estimation instead of a sensor, could open up new possibilities for control. This paper proposes a turbo speed estimator that only utilizes the conditions around the compressor and a model for the compressor map. These conditions are measured or can be more easily estimated from available sensors than the conditions on the turbine side. Another approach would be to estimate the turbo speed from the torque balance on the turbo shaft, but this requires estimating the torque provided by the turbine.
2017-03-28
Technical Paper
2017-01-0593
Ivan Arsie, Rocco Di Leo, Cesare Pianese, Matteo De Cesare
The development of more affordable sensors together with the enhancement of computation features in current Engine Management Systems (EMS), makes the in-cylinder pressure sensing a suitable methodology for the on-board engine control and diagnosis. Since the 1960’s the in-cylinder pressure signal was employed to investigate the combustion process of the internal combustion engines for research purposes. Currently, the sensors cost reduction in addition to the need to comply with the strict emissions legislation has promoted a large-scale diffusion on production engines equipment. The in-cylinder pressure signal offers the opportunity to estimate with high dynamic response almost all the variables of interest for an effective engine combustion control even in case of non-conventional combustion processes (e.g. PCCI, HCCI, LTC).
2017-03-28
Journal Article
2017-01-0596
Vittorio Ravaglioli, Federico Stola, Matteo De Cesare, Fabrizio Ponti, Stefano Sgatti
Upcoming more stringent emission regulations throughout the world represent a real challenge, especially in case of Diesel systems for passenger cars, where the need of additional aftertreatment has a big impact in term of additional system cost and available packaging space. Therefore, the need for strategies that allow managing combustion towards lower emissions, that require a precise control of the combustion outputs, is definitely increasing. Acoustic emission of internal combustion engines contains many information related to engine behavior and working conditions. Mechanical noise and combustion noise are usually the main contributions to the noise produced by an engine. A recent research from the same authors of this paper demonstrated that the combustion noise in particular can be used as an indicator of the combustion that is taking place inside the combustion chamber and therefore as a reference for the control strategy.
2017-03-28
Journal Article
2017-01-0581
Stephen C. Burke, Matthew Ratcliff, Robert McCormick, Robert Rhoads, Bret Windom
In some studies a relationship has been observed between increasing ethanol content in gasoline and increased particulate matter (PM) emissions from vehicles equipped with spark ignition engines. Ethanol features a greater enthalpy of vaporization (HOV) than gasoline and is commonly used in gasoline blends. In addition to increasing HOV, ethanol also influences vaporization by altering the liquid and vapor composition throughout the distillation process. A droplet vaporization model was developed to explore ethanol’s effect on the evaporation of aromatic compounds known to be PM precursors. The evolving droplet composition is being modeled as a distillation process, with non-ideal interactions between oxygenates and hydrocarbons accounted for using UNIFAC group contribution theory. Predicted composition and distillation curves were validated by experiments.
2017-03-28
Journal Article
2017-01-0586
Hayato Shirai, Hayato Nakada, Akio Matsunaga, Hiroyuki Tominaga
In real-world automotive control, there are a lot of constraints to be considered. In order to explicitly treat the constraints, we introduce a model-prediction-based algorithm called a reference governor (RG). The RG generates modified references so that predicted future variables in a closed-loop system satisfy their constraints. One merit of introducing the RG is that effort required in control development and calibration would be reduced. In the preceding research work by Nakada et al., only a single reference case was considered. However, it is difficult to extendedly apply it to more complicated systems with multiple references such as the air path control of a diesel engine, which suffers from interference between boosting and exhaust gas recirculation (EGR) systems. Moreover, in the control, multiple constraints need to be considered to ensure hardware limits and control performance.
2017-03-28
Journal Article
2017-01-0583
Farraen Mohd Azmin, Phil Mortimer, Justin Seabrook
With the introduction in Europe of drive cycles such as RDE and WLTC, transient emissions prediction is more challenging than for the NEDC. Transient predictions are used in the calibration optimisation process to determine the cumulative cycle emissions for the purpose of meeting objectives and constraints. Predicting emissions such as soot accurately is the most difficult area, because soot emissions rise very steeply during certain transients. Besides model accuracy, prediction time also is also important when applying a dynamic model because the optimisation process can take a significant amount of time to converge to a solution that satisfies all constraints. The method proposed in this paper is an evolution of prediction using a steady state global model. A dynamic model can provide the instantaneous prediction of boost and EGR that a static model cannot. Meanwhile, a static model is more accurate for steady state engine emissions.
2017-03-28
Journal Article
2017-01-0598
Mohammad Reza Amini, Meysam Razmara, Mahdi Shahbakhti
Electronic throttle control is an integral part of an engine control unit (ECU) that directly affects vehicle fuel economy, drivability, and engine-out emissions by managing engine torque and air-fuel ratio through adjusting intake charge flow to the engine. The highly nonlinear dynamics of the throttle body call for nonlinear control techniques that can be implemented in real-time and are also robust to controller implementation imprecision. Discrete sliding mode control (DSMC) is a computationally efficient controller design technique which can handle systems with high degree of nonlinearity. In this paper, a robust DSMC is designed and experimentally verified for the throttle position tracking problem. A novel method is used to predict and incorporate the sampling and quantization imprecisions into the DSMC structure. In this paper, a nonlinear physical model for an electromechanical throttle body is derived.
2017-03-28
Technical Paper
2017-01-0778
Vishnu Vijayakumar, P. Sakthivel, Bhuvenesh Tyagi, Amardeep Singh, Reji Mathai, Shyam Singh, Ajay Kumar Sehgal
In the light of major research work carried out on the detrimental health impacts of ultrafine particles (<50 nm), Euro VI emission standards incorporate a limit on particle number, of which ultrafine particles is the dominant contributor. With large reserves of natural gas available together with lesser fuel costs and emission impact, there has been a steady increase in the number of CNG vehicles on road .Considering the fact that CNG is a neat fuel, the dominant contributor toward particle emissions is due to combustion of the lubricant. The oil transport mechanisms into the combustion chamber vary with engine operating conditions as well as with the physico chemical properties of the lubricant. The present study investigates the mechanism of nucleation, effect of oil viscosity & ageing on the size as well as particle number concentration on a heavy duty 230hp Cummins gas engine.
2017-03-28
Journal Article
2017-01-1221
Shingo Soma, Haruhiko shimizu, Eiji Shirado, Satoshi Fujishiro
There have been calls for the automotive industry to reduce CO2 emissions in consideration of the impact on the global environment, and increasing efforts are being made to develop electric vehicles. Heavy rare earth - iron - boron magnets (neodymium magnets) have the largest maximum energy product (BH)max among current magnets, and are used in the driving motors of hybrid electric vehicles and electric vehicles. However, these operating environments have high temperatures and strong diamagnetic fields, so magnets need high heat resistance, or high coercive force (Hcj). To support this need, heavy rare earth elements (Dy, Tb) with high anisotropic magnetic fields are added to increase Hcj. However, deposits of these elements are unevenly distributed around the world and the ratio of heavy rare earth elements in ores is one tenth or less that of light rare earth elements.
2017-03-28
Journal Article
2017-01-1249
Masahiro Seguchi
Compact, high efficiency and high reliability is required for an xEV motor generator. IPM rotors with neodymium magnet are widely applied for xEV motors to achieve these requirements. However, the neodymium magnet material has a big impact on motor cost and there is supply chain risk due to increased usage of these rare earth materials for future automotive xEV’s. On the other hand, a wound-field rotor does not need magnets and can achieve equivalent performance to an IPM rotor. However, brushes are required in order to supply current to the winding coil of the rotor. This may cause insulation issues on xEV motors which utilize high voltage and high currents. Therefore, it can be suggested to develop a system which supplies electric energy to the rotor field winding coil from stator without brushes by applying a transformer between stator coil and rotor field winding. Specifically, add auxiliary magnetic poles between each field winding poles and wind sub-coils to these poles.
2017-03-28
Technical Paper
2017-01-0975
Pankaj Kumar, Imad Makki
A three-way catalytic converter (TWC) is used for emissions control in a gasoline engine. The conversion efficiency of the catalyst, however, drops with age or customer usage and needs to be monitored on-line to meet the on board diagnostics (OBD II) regulations. In this work, a non-intrusive catalyst monitor is developed to track the remaining useful life of the catalyst based on measured in-vehicle signals. Using air mass and the air-fuel ratio (A/F) at the front (upstream) and rear (downstream) of the catalyst, the catalyst oxygen storage capacity is estimated. The catalyst capacity and operating exhaust temperature are used as an input features for developing a Support Vector Machine (SVM) algorithm based classifier to identify a threshold catalyst. In addition, the distance of the data points in hyperspace from the calibrated threshold plane is used to compute the remaining useful life left.
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