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2017-03-28
Technical Paper
2017-01-0957
Ian Smith, Thomas Briggs, Christopher Sharp, Cynthia Webb
Abstract It is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards of 0.20 g/bhp-hr, the National Ambient Air Quality Standards (NAAQS) requirements for ambient ozone will not be met. It is expected that further reductions in NOX emissions from the heavy-duty fleet will be required to achieve compliance with the ambient ozone requirement. To study the feasibility of further reductions, the California Air Resources Board (CARB) funded a research program to demonstrate the potential to reach 0.02 g/bhp-hr NOX emissions. This paper details the work executed to achieve this goal on the heavy-duty Federal Test Procedure (FTP) with a heavy-duty natural gas engine equipped with a three-way catalyst. A Cummins ISX-12G natural gas engine was modified and coupled with an advanced catalyst system.
2017-03-28
Technical Paper
2017-01-0971
Uladzimir Budziankou, Thomas Lauer, Xuehai Yu, Brian M Schmidt, Nam Cho
Experimental studies have shown that knitted wiremesh mixers reduce the formation of solid deposits and improve ammonia homogenization in automotive SCR systems. However, their implementation in CFD models remains a major challenge due to the complex WM geometry. It was the aim of the current study to investigate droplet WM interaction. Essential processes, such as secondary droplet generation, wall film formation, and heat exchange, were analyzed in detail and a numerical model was set up. A box with heat resisting glass was used to study urea-water solution spray impingement on a WM under a wide range of operating conditions. High speed videography was used to identify the impingement regimes. Infrared thermography was applied to investigate WM cooling. In order to determine the impact of the WM on the spray characteristics, the droplet spectrum was measured both upstream and downstream of the WM using the laser diffraction method.
2017-03-28
Technical Paper
2017-01-0968
Anand Srinivasan, Saurabh Joshi, Yadan Tang, Di Wang, Neal Currier, Aleksey Yezerets
Abstract Commercial Cu-Zeolite SCR catalyst can store and subsequently release significant amount of H2O. The process is accompanied by large heat effects. It is critical to model this phenomenon to design aftertreatment systems and to provide robust tuning strategies to meet cold start emissions and low temperature operation. The complex reaction mechanism of water adsorption and desorption over a Cu-exchanged SAPO-34 catalyst at low temperature was studied through steady state and transient experiments. Steady state isotherms were generated using a gravimetric method and then utilized to predict water storage interactions with respect to feed concentration and catalyst temperature. Transient temperature programmed desorption (TPD) experiments provided the kinetic information required to develop a global kinetic model from the experimental data. The model captures fundamental characteristics of water adsorption and desorption accompanied by the heat effects.
2017-03-28
Technical Paper
2017-01-0976
Seun Olowojebutu, Thomas Steffen
Abstract The integration of selective catalytic reduction catalysts (SCR) into diesel particulate filters (DPF) as a way to treat nitrogen oxides (NOx) and particulate matter (PM) emission is an emerging technology in diesel exhaust aftertreatment. This is driven by ever-tightening limits on NOx and PM emission. In an integrated SCR-in-DPF (also known as SCRF®, SCR-on-DPF, SDPF, or SCR coated filter), the SCR catalyst is impregnated within the porous walls of the DPF. The compact, low weight/volume of the integrated unit provides improvement in the diesel engine cold start emission performance. Experimental investigations have shown comparable performance with standard SCR and DPF units for NOx conversion and PM control, respectively. The modelling of the integrated unit is complicated.
2017-03-28
Technical Paper
2017-01-0988
Michael Cunningham, Mi-Young Kim, Venkata Lakkireddy, William Partridge
Abstract Measuring axial exhaust species concentration distributions within a wall-flow aftertreatment device provides unique and significant insights regarding the performance of complex devices like the SCR-on-filter. In this particular study, a less complex aftertreatment configuration which includes a DOC followed by two uncoated partial flow filters (PFF) was used to demonstrate the potential and challenges. The PFF design in this study was a particulate filter with alternating open and plugged channels. A SpaciMS [1] instrument was used to measure the axial NO2 profiles within adjacent open and plugged channels of each filter element during an extended passive regeneration event using a full-scale engine and catalyst system. By estimating the mass flow through the open and plugged channels, the axial soot load profile history could be assessed.
2017-03-28
Technical Paper
2017-01-0992
Dereck Dasrath, Richard Frazee, Jeffrey Hwang, William Northrop
Abstract Partially premixed low temperature combustion (LTC) in diesel engines is a strategy for reducing soot and NOX formation, though it is accompanied by higher unburned hydrocarbon (UHC) emissions compared to conventional mixing-controlled diesel combustion. In this work, two independent methods of quantifying light UHC species from a diesel engine operating in early LTC (ELTC) modes were compared: Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS). A sampling system was designed to capture and transfer exhaust samples for off-line GC-MS analysis, while the FT-IR sampled and quantified engine exhaust in real time. Three different ELTC modes with varying levels of exhaust gas recirculation (EGR) were implemented on a modern light-duty diesel engine. GC-MS and FT-IR concentrations were within 10 % for C2H2, C2H4, C2H6, and C2H4O. While C3H8 was identified and quantified by the FT-IR, it was not detected by the GCMS.
2017-03-28
Technical Paper
2017-01-0997
Roberto Aliandro Varella, Gonçalo Duarte, Patricia Baptista, Luis Sousa, Pablo Mendoza Villafuerte
Abstract The gap between regulated emissions from vehicle certification procedures and real-world driving has become increasingly wider, particularly for nitrogen oxides (NOx). Even though stricter emission regulations have been implemented, NOx emissions are dependent on specific, short-duration driving events which are difficult to control, therefore high concentrations of these pollutants are still being measured in European cities. Under certification procedures, vehicle emissions compliance is evaluated through standards, recurring to driving cycles performed on chassis dynamometer under controlled laboratory conditions. Different countries use different standard cycles, with the US basing their certification cycle on FTP-75 and Europe using NEDC (Euro 5/6c)/WLTP (Euro 6d).
2017-03-28
Technical Paper
2017-01-1003
Ye Liu, Gang Lv, Chenyang Fan, Na Li, Xiaowei Wang
Abstract The evolution of surface functional groups (SFGs) and the graphitization degree of soot generated in premixed methane flames are studied and the correlation between them is discussed. Test soot samples were obtained from an optimized thermophoretic sampling system and probe sampling system. The SFGs of soot were determined by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) after removing the soluble impurities from the soot samples, while the graphitization degree of soot was characterized by Raman spectrum and electron energy loss spectroscopy (EELS). The results reveal that the number of aliphatic C-H groups and C=O groups shows an initial increase and then decrease in the sooting history. The large amount of aliphatic C-H groups and small amount of aromatic C-H groups in the early stage of the soot mass growth process indicate that aliphatic C-H groups make a major contribution to the early stage of soot mass growth.
2017-03-28
Technical Paper
2017-01-1004
Jan Czerwinski, Pierre Comte, Norbert Heeb, Andreas Mayer, Volker Hensel
Abstract In the present paper some results of investigations of nanoparticles from five DI gasoline cars are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. Moreover, five variants of “vehicle - GPF” were investigated. These results originate from the project GasOMeP (Gasoline Organic & Metal Particulates), which focused on metal-nanoparticles (including sub 20nm) from gasoline cars with different engine technologies. The PN-emission level of the investigated GDI cars in WLTC without GPF is in the same range of magnitude very near to the actual limit value of 6.0 × 1012 #/km. With the GPF’s with better filtration quality, it is possible to lower the emissions below the future limit value of 6.0 × 1011 #/km. There is no visible nuclei mode and the ultrafine particle concentrations below 10mm are insignificant. Some of the vehicles show at constant speed operation a periodical fluctuation of the NP-emissions, as an effect of the electronic control.
2017-03-28
Technical Paper
2017-01-0179
Saravanan Sambandan, Manuel Valencia, Sathish Kumar S
Abstract In current automotive industry, the necessity of providing quick warm up of the cabin during extreme cold conditions becomes more challenging to the engineers. A Trade-off between development time, cost and desired performance has to be achieved for deciding the right combination of HVAC (Heating ventilating air-conditioning) components to meet the customer satisfaction. In the HVAC, heater system plays a major role during winter condition to provide passenger comforts as well as to clear windshield defogging/deicing. The heater system consists of heater core, engine coolant as inner medium and air as outer medium. The coolant is circulated by engine coolant/water pump carrying heat from engine and flows across the heater core. The HVAC blower provides air to the cabin by taking heat from the heater core through floor duct systems thus warm up the cabin.
2017-03-28
Journal Article
2017-01-0246
Sentao Miao, Xiuli Chao, Michael Tamor, Yan Fu, Margaret Strumolo
Most of the greenhouse gas (GHG) emissions in the United States come from the transportation and electricity generation sectors. In this paper, we analyzed the possibility of cross-sector cooperation to cost-efficiently reduce these emissions. Specifically, we built a bi-level optimization model with renewable energy certificate (REC) purchasing to evaluate the effectiveness of the REC purchasing policy. This policy allows the transportation sector to purchase RECs, which are created by renewable generators built by the electricity generation sector, in order to gain extra emission allowance. We conclude from simulations that REC purchasing policy helps to lower the total cost to society while reducing GHG emissions significantly. Simulation results also show that REC purchasing policy can create electricity capacity beyond demand, which can potentially be used to make clean fuel and further cut emissions from existing fossil fuel powered vehicles.
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
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
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
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
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
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.
2017-03-28
Technical Paper
2017-01-0960
Pankaj Kumar, Imad Makki
Traditionally, a three-way catalyst (TWC) is controlled to a set heated exhaust gas oxygen (HEGO) sensor voltage (typically placed after the monitored catalyst) that corresponds to optimal catalyst efficiency. This limits the control action, as we rely on emissions breakthrough at the HEGO sensor to infer the state of catalyst. In order to robustly meet the super ultra-low emission regulations, a more precise TWC control around the oxidation level of catalyst is desirable. In this work, we developed a comprehensive set of models to predict the oxygen storage capacity using measured in-vehicle signals only. This is accomplished by developing three models; the first model is a linear in parameter regression model to predict the feed gas emissions from measured signals like engine speed and air-to-fuel ratio (A/F). The second model is a low-dimensional physics based model of the three-way catalyst to predict the exhaust emissions and oxidation state of the catalyst.
2017-03-28
Technical Paper
2017-01-1166
Gareth Milton, Paul Bloore, Khizer Tufail, Barnaby Paul Coates, Ian Newbigging, Allan Cooper, Paul Shayler
Abstract In order to achieve fleet average CO2 targets, mass-market adoption of low CO2 technologies is required. Application of low cost technologies across a large number of vehicles is more cost-effective in reducing fleet CO2 than deploying high-impact, costly technology to a few. Therefore, to meet the CO2 reduction challenge, commercially viable, low cost technologies are of significant interest. This paper presents results from the ‘ADEPT’ collaborative research program which focuses on CO2 reduction through the application of intelligent 48V electrification to diesel engines for passenger car applications. Results were demonstrated on a C-segment vehicle with a class-leading 4-cylinder 1.5 litre Euro 6 diesel engine. Electrification was applied through a high power, high efficiency, switched reluctance belt-integrated starter generator (B-ISG) capable of both generation and motoring, and an Advanced Lead Carbon Battery for energy storage.
2017-03-28
Technical Paper
2017-01-0684
Vickey B. Kalaskar, Raphael Gukelberger, Bradley Denton, Thomas Briggs
Dedicated Exhaust Gas Recirculation (D-EGR) has shown a lot of promise in multi-cylinder engines . In this study a 4-cylinder turbocharged GDI engine was modified to a D-EGR configuration. The aim of the study was to understand the effects of valve phasing and different injection strategies on the reformate production in the dedicated cylinder, and the engine performance. This engine with positive valve overlap capability gave the best platform to study reformate from the dedicated cylinder at various valve phasing and fuel injection strategies with provisions for individual cylinder control for both PFI and DI injection systems. Three speed-load combinations were studied, 2000 rpm 4 bar IMEPg, 2000 rpm 12 bar IMEPg, and 4000 rpm 12 bar IMEPg. This paper can be divided into 2 parts.
2017-03-28
Technical Paper
2017-01-0875
Valentin Soloiu, Jose Moncada, Martin Muinos, Aliyah Knowles, Remi Gaubert, Thomas Beyerl, Gustavo Molina
This paper investigates the performance of an indirect injection (IDI) diesel engine fueled with Bu25, 75% ultra-low sulfur diesel (ULSD#2) blended with 25% n-butanol by mass. N-butanol, derivable from biomass feedstock, was used given its availability as an alternative fuel that can supplement the existing limited fossil fuel supply. Combustion and emissions were investigated at 2000 rpm across loads of 4.3-7.2 bar indicated mean effective pressure (IMEP). Cylinder pressure was collected using Kistler piezoelectric transducers in the precombustion (PC) and main combustion (MC) chambers. Ignition delays ranged from 0.74 - 1.02 ms for both operated fuels. Even though n-butanol has a lower cetane number, the high swirl in the separate combustion chamber would help advance its premixed combustion. The heat release rate of Bu25 became initially 3 J/crank-angle-degree (CAD) higher than that of ULSD#2 as load increased to 7.2 bar IMEP.
2017-03-28
Technical Paper
2017-01-0917
Go Hayashita, Motoki Ohtani, Keiichiro Aoki, Shuntaro Okazaki
Trying to prevent global warming and air pollution, Toyota has led the world in the field of after treatment technologies including the three-way catalyst (TWC) system with oxygen sensor. In this study, a new emission control system for Toyota New Global Architecture (TNGA) Engine which brings lower fuel consumption and higher performance for creating ever-better cars is reported. The new system was adopted the exhaust cooling system and small capacity TWC. These can achieve a balance between heating TWC for early activation and cooling TWC for protection. As a result, regardless of the platform or the unit type of the vehicle, it is possible to unify the catalyst temperature which is a key parameter in the exhaust gas purification. In order to reduce emission also with the small capacity TWC, it is necessary to a high accuracy air-fuel ratio (A/F) control.
2017-03-28
Technical Paper
2017-01-1400
Keyu Qian, Gangfeng Tan, Renjie Zhou, Binyu Mei, Wanyang XIA
Abstract Downhill mountain roads are the accident prone sections because of their complexity and variety. Drivers rely more on driving experience and it is very easy to cause traffic accidents due to the negligence or the judgment failure. Traditional active safety systems, such as ABS, having subjecting to the driver's visual feedback, can’t fully guarantee the downhill driving safety in complex terrain environments. To enhance the safety of vehicles in the downhill, this study combines the characteristics of vehicle dynamics and the geographic information. Thus, through which the drivers could obtain the safety speed specified for his/her vehicle in the given downhill terrains and operate in advance to reduce traffic accidents due to driver's judgment failure and avoid the brake overheating and enhance the safety of vehicles in the downhill.
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 before for passenger car applications. Transient predictions are used in the calibration optimization 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. The method described 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. Combining these two model types allows more accurate prediction of emissions against time. A global dynamic model combines a dynamic model of the engine air path with a static DoE (Design of Experiment) emission model.
2017-03-28
Technical Paper
2017-01-0127
Norimitsu Matsudaira, Mitsuru Iwasaki, Junichiro Hara, Tomohiko Furuhata, Tatsuya Arai, Yasuo Moriyoshi, Naohiro Hasegawa
Among the emerging technologies in order to meet ever stringent emission and fuel consumption regulations, Exhaust Gas Recirculation (EGR) system is becoming one of the prerequisites particularly for diesel engines. Although an EGR cooler is considered to be an effective measure for further performance enhancement, exhaust gas soot deposition may cause degradation of the cooling. To address this issue, the authors studied the visualization of the soot deposition phenomenon to understand its behavior. Based on thermophoresis theory, which indicates that the effect of thermophoresis depends on the temperature difference between gas and the wall surface exposed to the gas, a new visualization method using a heated glass window was developed. By using glass with the transparent conductive oxide: tin-doped indium oxide , temperature of the heated glass surface is raised.
2017-03-28
Technical Paper
2017-01-0511
Tianhao Yang, Lianhao Yin, Gabriel Ingesson, Per Tunestal, Rolf Johansson, Wuqiang Long
Abstract In this paper, a control-oriented soot model was developed for real-time soot prediction and combustion condition optimization in a gasoline Partially Premixed Combustion (PPC) Engine. PPC is a promising combustion concept that achieves high efficiency, low soot and NOx emissions simultaneously. However, soot emissions were found to be significantly increased with high EGR and pilot injection, therefore a predictive soot model is needed for PPC engine control. The sensitivity of soot emissions to injection events and late-cycle heat release was investigated on a multi-cylinder heavy duty gasoline PPC engine, which indicated main impact factors during soot formation and oxidation processes. The Hiroyasu empirical model was modified according to the sensitivity results, which indicated main influences during soot formation and oxidation processes. By introducing additional compensation factors, this model can be used to predict soot emissions under pilot injection.
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.
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