scholarly journals Developing a Traffic Model to Estimate Vehicle Emissions: An Application in Seoul, Korea

2021 ◽  
Vol 13 (17) ◽  
pp. 9761
Author(s):  
Hanghun Jo ◽  
Heungsoon Kim
Keyword(s):  
High Speed ◽  
High Ratio ◽  
Liquefied Petroleum Gas ◽  
Demand Model ◽  
Passenger Cars ◽  
Traffic Demand ◽  
Diesel Vehicles ◽  
Restriction Policy ◽  
Speed Range ◽  
Reduce Emissions

In this study, a traffic demand model was created based on a simulation network, and another model was built to calculate exhaust-gas emissions generated by vehicles based on the emission function. Subsequently, emissions for three scenarios were analyzed based on the traffic restriction policy according to the vehicle grading system implemented in Seoul. According to the results of the analysis, emission reduction under the vehicle restriction policy was the highest among passenger cars in the low-speed range, while the emissions of cargo trucks in the high-speed range were found to be high. The emissions showed a high ratio of carbon monoxide and nitrogen oxides, and high emissions were generated from liquefied petroleum gas and diesel vehicles. Furthermore, the effects of vehicle restriction policy were confirmed to reduce emissions from diesel and other vehicle types. Using the established model, we were able to confirm that the vehicle restriction policy contributed to the improvement of air quality. Furthermore, the diesel vehicle restriction policy also had an impact on reducing the emissions of vehicle types other than those using diesel.

scholarly journals Improvement of passenger car power supply

2021 ◽  
Vol 2131 (4) ◽  
pp. 042086
Author(s):  
V V Nikitin ◽  
B A Trifonov
Keyword(s):  
Lower Limit ◽  
Power Supply ◽  
High Speed ◽  
Power Supply System ◽  
Technical Solution ◽  
Passenger Cars ◽  
Passenger Car ◽  
Dc Voltage ◽  
Speed Range ◽  
Pulse Converter

Abstract A significant part of the fleet of passenger cars in operation on Russian railways are equipped with an autonomous power supply system, in which the main source of energy is an undercar generator, which is rotated from the axle of a wheelset. The disadvantage of such a system is the limitation of the speed range in which it is possible to power consumers of electric power of a passenger car from the main source: as a rule, the lower limit of this range is 35 km/h. The article proposes a variant of a technical solution that will expand the speed range of using the undercar generator by lowering the lower limit to 25 km/h: it is proposed to provide self-excitation of the undercar generator through an inverting-type DC voltage pulse converter. The parameters of the elements of the pulse converter circuit and the possibility of expanding the boundaries of the high-speed range of operation of the EGV.08.1U1 undercar generator are estimated.

scholarly journals Electrical and Mechanical Characteristics of a High-Speed Motor for Electric Turbochargers in Relation to Eccentricity

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3340
Author(s):  
Tae-Woo Lee ◽  
Do-Kwan Hong
Keyword(s):  
Climate Change ◽  
High Speed ◽  
Mechanical Characteristics ◽  
High Efficiency ◽  
Fuel Efficiency ◽  
Permanent Magnet Synchronous Motor ◽  
Simple Method ◽  
Diesel Vehicles ◽  
Reduce Emissions ◽  
Transportation Technologies

As the demand for eco-friendly, high-efficiency transportation technologies increase due to climate change, a high-speed electric motor, a key component of an electric turbocharger, has been developed that can reduce emissions and increase fuel efficiency. Korea Electrotechnology Research Institute with Keyyang Precision Co., Ltd., developed a high-speed surface-mounted permanent magnet synchronous motor. It operates at a power of 3 kW at 100,000 rpm and is intended to fit 1600 cc diesel vehicles. In this paper, the electrical and mechanical characteristics of the high-speed motor were reviewed in consideration of the effect of eccentricity among the various causes that affect vibration. It was confirmed that eccentricity affected the distribution of the electromagnetic force and inductance of the winding due to the uneven air-gap. Additional vibration was generated at the half of pole passing frequency (1666.67 Hz). Diagnosing the presence or absence of eccentricity when driving a motor takes a great deal of time and cost because the load is separated or the motor is diagnosed through disassembly and measurement. The characteristics of eccentricity identified in this paper can be checked using a relatively simple method when diagnosing the presence or absence of actual eccentricity.

scholarly journals Optimization and Comparative Analysis of Traffic Restriction Policy by Jointly Considering Carpool Exemptions

2020 ◽  
Vol 12 (18) ◽  
pp. 7734
Author(s):  
Xueyan Wei ◽  
Weijie Yu ◽  
Wei Wang ◽  
De Zhao ◽  
Xuedong Hua
Keyword(s):  
Comparative Analysis ◽  
Traffic Congestion ◽  
Management Policy ◽  
Public Acceptance ◽  
License Plate ◽  
Demand Model ◽  
Compensatory Mitigation ◽  
Traffic Demand ◽  
The Public ◽  
Restriction Policy

As a countermeasure to urban exhaust pollution and traffic congestion, traffic restriction policy (TRP) and carpooling strategy have been widely introduced throughout the world. However, their effects are largely determined by the rationality of implementing policies, and unreasonable policies make them controversial on the long-term implementation benefits. To more effectively manage traffic demand and maintain the sustainability of transportation system, it is necessary to make optimization for management policy before implementation. In this paper, the elastic demand model and equilibrium assignment model are developed under TRP. Considering the negative impact of the mandatory TRP on the public acceptance, we propose a novel TRP strategy, namely TRP with carpool exemptions (TRP-CE), that is, a proportion of high occupancy vehicles (HOV) are allowed to travel in the restricted district even if their license plate numbers are restricted. Then, a bi-level programming model is proposed to solve the optimal schemes by combining multi purposes of ensuring travel convenience, alleviating traffic congestion, and reducing the exhaust pollution. Finally, a numerical experiment is conducted to evaluate the effectiveness of proposed models and make comparative analysis between separate TRP and TRP-CE. The results indicate that TRP-CE has benefits in the following aspects: (1) Carpool exemptions provide an incentive to carpool for travelers by private cars; (2) the public acceptance of TRP is improved by introducing carpool exemptions as a compensatory mitigation strategy for mandatory TRP; (3) the implementation effect of demand management can be well achieved by joint optimization; and (4) there is no need to design and reconstruct HOV lanes for the implementation of TRP-CE, which is convenient for practical application.

scholarly journals High-enthalpy hypersonic flows

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Joseph J. S. Shang ◽  
Hong Yan
Keyword(s):  
Hypersonic Flow ◽  
High Speed ◽  
Quantum Physics ◽  
Nonequilibrium Thermodynamic ◽  
Strong Shock ◽  
Hypersonic Flows ◽  
Electrically Conducting ◽  
High Enthalpy ◽  
Speed Range ◽  
Flow Theories

Abstract Nearly all illuminating classic hypersonic flow theories address aerodynamic phenomena as a perfect gas in the high-speed range and at the upper limit of continuum gas domain. The hypersonic flow is quantitatively defined by the Mach number independent principle, which is derived from the asymptotes of the Rankine-Hugoniot relationship. However, most hypersonic flows encounter strong shock-wave compressions resulting in a high enthalpy gas environment that always associates with nonequilibrium thermodynamic and quantum chemical-physics phenomena. Under this circumstance, the theoretic linkage between the microscopic particle dynamics and macroscopic thermodynamics properties of gas is lost. When the air mixture is ionized to become an electrically conducting medium, the governing physics now ventures into the regimes of quantum physics and electromagnetics. Therefore, the hypersonic flows are no longer a pure aerodynamics subject but a multidisciplinary science. In order to better understand the realistic hypersonic flows, all pertaining disciplines such as the nonequilibrium chemical kinetics, quantum physics, radiative heat transfer, and electromagnetics need to bring forth.

Torque imporvement of IPM motors with skewing magnetic designs

2021 ◽  
pp. 3-10
Author(s):  
Dinh Hai Linh
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Torque Ripple ◽  
Maintenance Cost ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Speed Range ◽  
Interior Permanent Magnet ◽  
Interior Permanent Magnet Motor ◽  
Wide Speed Range

In this paper, a type interior permanent magnet synchronous motor designs is proposed for sport scooter application to improve constant torque wide speed performance. Interior Permanent Magnet machines are widely used in automotive applications for their wide-speed range operation and low maintenance cost. An existing permanent magnet motor (commercial QS Motor) is 3 kW-3000 rpm. In order to improve torque and power in wide speed range, a IPM electric motor 5.5 kW -5000 rpm can run up to 100 km/h: An Step-Skewing Interior Permanent Magnet motor alternatives is designed and optimized in detail with optimal magnetic segment V shape. The electromagnetic charateristics of Interior Permanent Magnet motors with V shape are compared with the reference Surface Permanent Magnet motor for the same geometry parameter requirements. Detailed loss and efficiency result is also analyzed at rate and maximum speeds. A prototype motor is manufactured, and initial experimental tests are performed. Detailed comparison between Finite Element Analysis and test data are also presented. It is shown that it is possible to have an optimized Interior Permanent Magnet motor for such high-speed traction application. This paper will figure out optimal angle of magnetic V shape for maximum torque and minimum torque ripple.

scholarly journals A Study on Characteristic Emission Factors of Exhaust Gas from Diesel Locomotives

2020 ◽  
Vol 17 (11) ◽  
pp. 3788 ◽  
Author(s):  
Min-Kyeong Kim ◽  
Duckshin Park ◽  
Minjeong Kim ◽  
Jaeseok Heo ◽  
Sechan Park ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Environmental Protection Agency ◽  
High Speed ◽  
Emission Factors ◽  
Exhaust Emission ◽  
Emission Measurement ◽  
Exhaust Gas ◽  
Diesel Locomotive ◽  
Diesel Vehicles ◽  
Engine Power

Use of diesel locomotives in transport is gradually decreasing due to electrification and the introduction of high-speed electric rail. However, in Korea, up to 30% of the transportation of passengers and cargo still uses diesel locomotives and diesel vehicles. Many studies have shown that exhaust gas from diesel locomotives poses a threat to human health. This study examined the characteristics of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons in diesel locomotive engine exhaust. Emission concentrations were evaluated and compared with the existing regulations. In the case of PM and NOx, emission concentrations increased as engine output increased. High concentrations of CO were detected at engine start and acceleration, while hydrocarbons showed weakly increased concentrations regardless of engine power. Based on fuel consumption and engine power, the emission patterns of PM and gaseous substances observed in this study were slightly higher than the U.S. Environmental Protection Agency Tier standard and the Korean emission standard. Continuous monitoring and management of emissions from diesel locomotives are required to comply with emission standards. The findings of this study revealed that emission factors varied based on fuel consumption, engine power, and actual driving patterns. For the first time, a portable emission measurement system (PEMS), normally used to measure exhaust gas from diesel vehicles, was used to measure exhaust gas from diesel locomotives, and the data acquired were compared with previous results. This study is meaningful as the first example of measuring the exhaust gas concentration by connecting a PEMS to a diesel locomotive, and in the future, a study to measure driving characteristics and exhaust gas using a PEMS should be conducted.

scholarly journals Characterizing Black Carbon Emissions from Gasoline, LPG, and Diesel Vehicles via Transient Chassis-Dynamometer Tests

2020 ◽  
Vol 10 (17) ◽  
pp. 5856
Author(s):  
Gyutae Park ◽  
Kyunghoon Kim ◽  
Taehyun Park ◽  
Seokwon Kang ◽  
Jihee Ban ◽  
...  
Keyword(s):  
Black Carbon ◽  
Coal Combustion ◽  
Gasoline Direct Injection ◽  
Environmental Research ◽  
Particulate Filter ◽  
Biomass Combustion ◽  
Liquefied Petroleum Gas ◽  
Chassis Dynamometer ◽  
Diesel Vehicles ◽  
Gasoline Vehicles

With global anthropogenic black carbon (BC) emissions increasing, automobiles are significantly contributing as the major source of emissions. However, the appropriate regulations of BC emissions from vehicles are not in place. This study examined BC emissions following fuel types (gasoline, liquefied petroleum gas (LPG), and diesel) and engine combustion (gasoline direct injection (GDI) and multi-port injection (MPI) for gasoline vehicles) with emission regulations. To this end, chassis dynamometer and aethalometer (AE33) were used. Driving modes created by the National Institute of Environmental Research (NIER) and emission certification modes (CVS-75 and NEDC) for vehicles in Korea were used to determine BC emissions for various vehicle speeds. In addition, the contributions of biomass and coal combustion to the data of AE33 were analyzed to determine the possibility of tracking the BC sources. MPI, LPG, and EURO 6 with diesel particulate filter (DPF) vehicles emitted the lowest BC emissions in NIER modes. Among gasoline vehicles, MPI vehicles showed the lower BC content in PM emissions. Also, older vehicles in MPI vehicles emitted the high PM and BC emissions. The BC emissions of EURO 3 vehicles without DPF were the highest as the results of previous studies, and it was found that as emissions regulations were tightened, the level of BC results of diesel vehicles became similar with MPI vehicles. The average absorption Ångström exponent (AAE) from difference emissions sources were biomass combustion (oak wood) > coal combustion (the power plant stack) > automobile emissions (gasoline, LPG, diesel).

scholarly journals Dual-Pulse Mode Control of a High-Speed Doubly Salient Electromagnetic Machine for Loss Reduction and Speed Range Extension

2020 ◽  
Vol 67 (6) ◽  
pp. 4391-4401
Author(s):  
Li Yu ◽  
Zhuoran Zhang ◽  
Zhangming Bian ◽  
David Gerada ◽  
Chris Gerada
Keyword(s):  
High Speed ◽  
Pulse Mode ◽  
Range Extension ◽  
Loss Reduction ◽  
Mode Control ◽  
Doubly Salient ◽  
Speed Range
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