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Technical Paper

Unregulated Emissions Evaluation of Gasoline Combustion Systems (Lean Burn / Stoichiometric DISI and MPI), State of the Art Diesel Aftertreatment Technologies (DPF, urea-SCR and DOC), and Fuel Qualities Effects (EtOH, ETBE, Aromatics and FAME)

2007-10-29
2007-01-4082
In order to clarify future automobile technologies and fuel qualities to improve air quality, second phase of Japan Clean Air Program (JCAPII) had been conducted from 2002 to 2007. Predicting improvement in air quality that might be attained by introducing new emission control technologies and determining fuel qualities required for the technologies is one of the main issues of this program. Unregulated material WG of JCAPII had studied unregulated emissions from gasoline and diesel engines. Eight gaseous hydrocarbons (HC), four Aldehydes and three polycyclic aromatic hydrocarbons (PAHs) were evaluated as unregulated emissions. Specifically, emissions of the following components were measured: 1,3-Butadiene, Benzene, Toluene, Xylene, Ethylbenzene, 1,3,5-Trimethyl-benzene, n-Hexane, Styrene as gaseous HCs, Formaldehyde, Acetaldehyde, Acrolein, Benzaldehyde as Aldehydes, and Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(k)fluoranthene as PAHs.
Technical Paper

The Study of Particle Number Reduction Using After-Treatment Systems for a Heavy-Duty Diesel Engine

2004-03-08
2004-01-1423
To reduce ultra fine particle number concentration from a heavy-duty diesel engine, the effects of diesel fuel property and after-treatment systems were studied. The reduction of ultra fine particle number concentration over steady state mode using an 8 liter turbocharged and after-cooled diesel engine was evaluated. PM size distribution was measured by a scanning mobility particle sizer (SMPS). The evaluation used a commercially available current diesel fuel (Sulfur Content: 0.0036 wt%), high sulfur diesel fuel (Sulfur Content: 0.046 wt%) and low sulfur diesel fuel (Sulfur Content: 0.007 wt%). The after-treatment systems were an oxidation catalyst, a wire-mesh type DPF (Diesel Particle Filter) and a wall-flow type catalyzed DPF. The results show that fine particle number concentration is reduced with a low sulfur fuel, an oxidation catalyst, a wire-mesh type DPF (Diesel Particulate Filter) and wall flow type catalyzed DPF, respectively.
Technical Paper

The Study of NOx and PM Reduction Using Urea Selective Catalytic Reduction System for Heavy Duty Diesel Engine

2007-04-16
2007-01-1576
To reduce NOx and Particulate Matter (PM) emissions from a heavy-duty diesel engine, the effects of urea selective catalytic reduction (SCR) systems were studied. Proto type urea SCR system was composed of NO oxidation catalyst, SCR catalyst and ammonia (NH3) reduction catalyst. The NOx reduction performance of urea SCR system was improved by a new zeolite type catalyst and mixer for urea distribution at the steady state operating conditions. NOx and PM reduction performance of the urea SCR system with DPF was evaluated over JE05 mode of Japan. The NOx reduction efficiency of the urea SCR catalyst system was 72% at JE05 mode. The PM reduction efficiency of the urea SCR catalyst system with DPF was 93% at JE05 mode. Several kinds of un-regulated matters were detected including NH3 and N2O leak from the exhaust gas. It is necessary to have further study for detailed measurements for un-regulated emissions from urea solution.
Technical Paper

The Study of NOx Reduction Using Plasma-assisted SCR System for a Heavy Duty Diesel Engine

2011-04-12
2011-01-0310
To reduce NOx emissions from a heavy-duty engine at low exhaust temperature conditions, the plasma-assisted SCR (Selective Catalytic Reduction) system was evaluated. The plasma-assisted SCR system is mainly composed of an ammonia gas supply system and a plasma reactor including a pellet type SCR catalyst. The preliminary test with simulated gases of diesel exhaust showed an improvement in the NOx reduction performance by means of the plasma-assisted SCR system, even below 150°C conditions. Furthermore, NOx reduction ratio was improved up to 77% at 110°C with increase in the catalyst volume. Also NOx emissions from a heavy-duty diesel engine over the transient test mode in Japan (JE05) were reduced by the plasma-assisted SCR system. However, unregulated emissions, e.g., aldehydes, were increased with the plasma environment. This paper reports the advantages and disadvantages of the plasma-assisted SCR system for a heavy-duty diesel engine.
Technical Paper

Study of 2-LEG NOx Storage-Reduction Catalyst System for HD Diesel Engine

2006-04-03
2006-01-0211
A 2-LEG NOx Storage-Reduction (NSR) catalyst system is one of potential after-treatment technology to meet stringent NOx and PM emissions standards as Post New Long Term (Japanese 2009 regulation) and US'10. Concerning NOx reduction using NSR catalyst, a secondary fuel injection is necessary to make fuel-rich exhaust condition during the NOx reduction, and causes its fuel penalty. Since fuel injected in the high-temperature (∼250 degrees Celsius) exhaust instantly reacts with oxygen in common diesel exhaust, the proportion of fuel consumption to reduce the NOx stored on NSR catalyst is relatively small. A 2-LEG NSR catalyst system has the decreasing exhaust flow mechanism during NOx reduction, and the potential to improve the NOx reduction and fuel penalty. Therefore, this paper studies the 2-LEG NSR catalyst system. The after-treatment system consists of NSR catalysts, a secondary fuel injection system, flow controlled valves and a Catalyzed Diesel Particulate Filter (CDPF).
Technical Paper

Steer-Restoring Torque Controlled Driving Simulator for Developing Steering Road Feel

1991-11-01
912690
A driving simulator system for developing steering road feel has been developed. A new steering gear box or an electronic steering system is installed on the simulator and its road feel and control algorithm are developed according to the characteristics of any vehicle which has been programed into the engineering work-station. The vehicle model programed into the engineering work station runs according to the driver's operations, which are fed through the new steering system to be tested. The steer-restoring torque of the vehicle programed into the engineering work-station is produced by an actuator, and gives the impression through the new system of having been fed back from an actual road.
Technical Paper

Simulation Techniques for Determining Motorcycle Controllability Class according to ISO 26262

2018-10-30
2018-32-0060
The ISO 26262 standard specifies the requirement for functional safety of electrical and electronic systems within road vehicles. We have accumulated case studies based on actual riding tests by subjective judgment of expert riders to define a method for determining the controllability class (C class). However, the wide variety of practical traffic environments and vehicle behaviors in case of malfunction make it difficult to evaluate all C classes in actual running tests. Furthermore, under some conditions, actual riding tests may cause unacceptable risks to test riders. In Part 12 Annex C of ISO/DIS 26262, simulation is cited as an example of a technique for comprehensive evaluations by the Controllability Classification Panel. This study investigated the usefulness of mathematical simulations for evaluating the C class of a motorcycle reproducing a malfunction in either the front or rear brakes.
Technical Paper

Research on bus passenger safety in frontal impacts

2001-06-04
2001-06-0210
Guidelines with regard to the body strength of buses have been drawn up in Japan. We now pass to the second step in research to assure the greater safety of bus crews and passengers by launching a study on further reduction of collision injuries to bus occupants. As a way to reduce such passenger injuries, our focus is the optimization of energy absorption, the arrangement of equipment on the passenger seat back, the seat frame construction, mounting and so on. The study was conducted using an experimental method together with FEM computer simulation. The findings from a sled impact test simulating a seat in a bus in a frontal collision are stated as follows. 1.Further consideration should be given to the present conventional ELR two-point seat belt. 2.One way to reduce passenger injury is to optimize the space between seats.
Journal Article

Prediction of Spray Behavior in Injected by Urea SCR Injector and the Reaction Products

2017-10-08
2017-01-2375
In the urea SCR system, urea solution is injected by injector installed in the front stage of the SCR catalyst, and NOx can be purified on the SCR catalyst by using NH3 generated by the chemical reaction of urea. NH3 is produced by thermolysis of urea and hydrolysis of isocyanic acid after evaporation of water in the urea solution. But, biuret and cyanuric acid which may cause deposit are sometimes generated by the chemical reactions without generating NH3. Spray behavior and chemical reaction of urea solution injected into the tail-pipe are complicated. The purpose of this study is to reveal the spray behavior and NH3 generation process in the tail-pipe, and to construct the model capable of predicting those accurately. In this report, the impingement spray behavior is clarified by scattered light method in high temperature flow field. Liquid film adhering to the wall and deposit generated after evaporation of water from the liquid film are photographed by the digital camera.
Technical Paper

Numerical Modeling of International Variations in Diesel Spray Combustion with Evaporation Surrogate and Virtual Species Conversion

2017-03-28
2017-01-0582
A methodology for simulating effect of international variations in fuel compositions on spray combustion is proposed. The methodology is validated with spray combustion experiments with real fuels from three different countries. The compositions of those fuels were analyzed through GC×GC and H-NMR. It was found that ignition delay times, flame region and flame luminosity were significantly affected by the compositional variations. For the simulation, an evaporation surrogate consisting of twenty two species, covering basic molecular types and a wide range of carbon numbers, is developed. Each species in the evaporation surrogate is then virtually converted to a reaction surrogate consisting of n-hexadecane, methylcyclohexane and 1,2,4-trimethyl benzene so that combustion reactions can be calculated with a published kinetic model. The virtual species conversion (VSC) is made so as to take over combustion-related properties of each species of evaporation surrogates.
Technical Paper

Nano Particle Emission Evaluation of State of the Art Diesel Aftertreatment Technologies (DPF, urea-SCR and DOC), Gasoline Combustion Systems (Lean Burn / Stoichiometric DISI and MPI) and Fuel Qualities Effects (EtOH, ETBE, FAME, Aromatics and Distillation)

2007-10-29
2007-01-4083
Newly designed laboratory measurement system, which reproduces particle number size distributions of both nuclei and accumulation mode particles in exhaust emissions, was developed. It enables continuous measurement of nano particle emissions in the size range between 5 and 1000 nm. Evaluations of particle number size distributions were conducted for diesel vehicles with a variety of emission aftertreatment devices and for gasoline vehicles with different combustion systems. For diesel vehicles, Diesel Oxidation Catalyst (DOC), urea-Selective Catalytic Reduction (urea-SCR) system and catalyzed Diesel Particulate Filter (DPF) were evaluated. For gasoline vehicles, Lean-burn Direct Injection Spark Ignition (DISI), Stoichiometric DISI and Multi Point Injection (MPI) were evaluated. Japanese latest transient test cycles were used for the evaluation: JE05 mode driving cycle for heavy duty vehicles and JC08 mode driving cycle for light duty vehicles.
Technical Paper

Modeling Study of Vehicle Emission Impacts on Air Quality - JCAP Air Quality Model Working Group Report

2003-05-19
2003-01-1864
Air Quality Modeling Working Group developed two models to evaluate effects of automobile emission reduction measures on air quality improvement: Urban Air Quality Simulation Model in which secondary aerosol formation processes have been incorporated, and Roadside Air Quality Simulation Model in which micro-scale traffic flow has been taken into consideration. Concretely, a model has been built up for estimating SPM concentration in ambient air in which high concentrated air pollutants have been contained during summer and winter. The model has been built up by using UAM (Urban Airshed Model) as base model, and the following modification has been made to the base model. First, ISSOROPIA (secondary inorganic aerosol equilibrium model) has been added to the base model, and a secondary organic aerosol formation/reaction model (SOA model) has been incorporated into the model.
Technical Paper

Large Eddy Simulation of Unsteady Flow Around a Formula Car on Earth Simulator

2007-04-16
2007-01-0106
One of the world's largest unsteady turbulence simulations of flow around a formula car was conducted using Large Eddy Simulation (LES) on the Earth Simulator in Japan. The main objective of our study is to investigate the validity of LES for the assessment of vehicle aerodynamics, as an alternative to a conventional wind tunnel measurement or the Reynolds Averaged Navier-Stokes (RANS) simulation. The aerodynamic forces estimated by LES show good agreement with the wind tunnel data (within several percent!) and various unsteady flow features around the car is visualized, which clearly indicate the effectiveness of large-scale LES in the very near future for the computation of flow around vehicles with complex configurations.
Technical Paper

Kinetic Measurements of HNCO Hydrolysis over SCR Catalyst

2018-09-10
2018-01-1764
To meet the strict emission regulations for diesel engines, an advanced processing device such as a Urea-SCR (selective catalytic reduction) system is used to reduce NOx emissions. The Real Driving Emissions (RDE) test, which is implemented in the European Union, will expand the range of conditions under which the engine has to operate [1], which will lead to the construction of a Urea-SCR system capable of reducing NOx emissions at lower and higher temperature conditions, and at higher space velocity conditions than existing systems. Simulations are useful in improving the performance of the urea-SCR system. However, it is necessary to construct a reliable NOx reduction model to use for system design, which covers the expanded engine operation conditions. In the urea-SCR system, the mechanism of ammonia (NH3) formation from injected aqueous urea solution is not clear. Thus, it is important to clarify this mechanism to improve the NOx reduction model.
Technical Paper

Japan Clean Air Program (JCAP): Preliminary Modeling Study of Vehicle Emission Impacts on Air Quality

1999-05-03
1999-01-1482
Comparing with the previous Auto/Oil programs, the total plan and current status of the air quality modeling study in JCAP are presented. The total plan of air quality modeling study has the following characteristics: 1) Vehicle emission inventory program is developed by considering the original features of Japan. 2) Not only the urban air quality but also the road sides pollutants dispersion is evaluated. 3) The chemical reaction model for the secondary particulate formations is developed on the basis of the smog chamber experiments. 4) For the cost-effectiveness analysis of vehicle/fuel technologies, the output of the air quality modeling will be combined with the cost data of new vehicle emission reduction technologies As the first step, preliminary modeling studies are conducted to understand the overall tendency of the air quality change toward 2010 in Tokyo urban area.
Technical Paper

Injury Pattern and Tolerance of Human Pelvis Under Lateral Loading Simulating Car-pedestrian Impact

2003-03-03
2003-01-0165
Numerous studies of pelvic tolerance to lateral impact aimed at protecting car occupants have been conducted on Post Mortem Human Subjects (PMHSs) in a sitting posture. However, it remains unclear whether or not the results of these studies are relevant when evaluating the injury risk to walking pedestrians impacted by a car. Therefore, the first objective of the present study is to determine the injury tolerance and to describe the injury mechanisms of the human pelvis in lateral impacts simulating car-pedestrian accidents. The second objective is to obtain data for validation of mathematical models of the pelvis. In-vitro experiments were conducted on twelve PMHSs in simulated standing position. The trochanter of each PMHS was hit by a ram at speed of 32 km/h, and the pelvic motion was constrained by a bolt. This type of pelvic constraint is difficult to simulate in mathematical models.
Journal Article

Influence of the Upper Body of Pedestrians on Lower Limb Injuries and Effectiveness of the Upper Body Compensation Method of the FlexPLI

2015-04-14
2015-01-1470
Current legform impact test methods using the FlexPLI have been developed to protect pedestrians from lower limb injuries in collisions with low-bumper vehicles. For this type of vehicles, the influence of the upper body on the bending load generated in the lower limb is compensated by setting the impact height of the FlexPLI 50 mm above that of pedestrians. However, neither the effectiveness of the compensation method of the FlexPLI nor the influence of the upper body on the bending load generated in the lower limb of a pedestrian has been clarified with high-bumper vehicles. In this study, therefore, two computer simulation analyses were conducted in order to analyze: (1) The influence of the upper body on the bending load generated in the lower limb of a pedestrian when impacted by high-bumper vehicles and (2) The effectiveness of the compensation method for the lack of the upper body by increasing impact height of the FlexPLI for high-bumper vehicles.
Technical Paper

Influence of Ferrocene on Engine and Vehicle Performance

2006-10-16
2006-01-3448
Ferrocene is used as an antiknock additive to replace lead alkyls. To clarify the influence of one metal additive, ferrocene, on engine, following experiments were carried out. The insulation resistance of spark plugs was measured, deposits in the engine were analyzed, and an exhaust emission and fuel economy tests were conducted using gasoline containing ferrocene. The deposit, which contained iron oxides, adhered to the combustion chamber, spark plugs, and exhaust pipe when the engine operated with gasoline containing ferrocene. When vehicles operated with gasoline containing ferrocene, fuel consumption increased and the exhaust temperature rose. In addition, an abnormal electrical discharge pattern was observed in spark plugs operating at high temperatures. Iron-oxide of Fe3O4 is changed into Fe2O3 under high temperatures. Discharge current flows in iron oxides including Fe2O3 because the conductivity of Fe2O3 increases at high temperatures.
Technical Paper

Improvement of Low-Temperature Performance of The NOx Reduction Efficiency on the Urea-SCR Catalysts

2013-04-08
2013-01-1076
Diesel engine has a good fuel economy and high durability and used widely for power source such as heavy duty in the world. On the other hand, it is required to reduce NOx (Nitrogen Oxides) and PM (Particulate Matter) emissions further from diesel exhaust gases to preserve atmosphere. The urea-SCR (Selective Catalytic Reduction) system is the most promising measures to reduce NOx emissions. DPF (Diesel Particulate Filter) system is commercialized for PM reduction. However, in case that a vehicle has a slow speed as an urban area driving, a diesel exhaust temperature is too low to activate SCR catalyst for NOx reduction in diesel emissions. Moreover, the diesel exhaust temperature becomes lower as a future engine has less fuel consumption. The purpose of this study is reduction of NOx emission from a heavy-duty diesel engine using the Urea SCR system at the low temperature.
Technical Paper

Impact of Oil-derived Sulfur and Phosphorus on Diesel NOx Storage Reduction Catalyst - JCAP II Oil WG Report

2006-10-16
2006-01-3312
Emission regulations for diesel-powered vehicles have been gradually tightening. Installation of after-treatment devices such as diesel particulate filters (DPF), NOx storage reduction (NSR) catalysts, and so on is indispensable to satisfy rigorous limits of particulate matter (PM) and nitrogen oxides (NOx). Japan Clean Air Program II Oil Working Group (JCAPII Oil WG) has been investigating the effect of engine oil on advanced diesel after-treatment devices. First of all, we researched the impact of oil-derived ash on continuous regeneration-type diesel particulate filter (CR-DPF), and already reported that the less sulfated ash in oil gave rise to lower pressure drop across CR-DPF [1]. In this paper, impact of oil-derived sulfur and phosphorus on NSR catalyst was investigated using a 4L direct injection common-rail diesel engine with turbo-intercooler. This engine equipped with NSR catalyst meets the Japanese new short-term emission regulations.
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