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Technical Paper

The Development of a NOx Reduction System during the Fuel Cut Period for Gasoline Vehicles

2019-04-02
2019-01-1292
Generally, vehicles do not need power during deceleration. Therefore, the fuel efficiency can be improved by stopping the fuel injection in this period. However, when the fuel cut is activated, NOx is emitted immediately after fuel cut. During the fuel cut period, a large amount of fresh air flows into the catalytic converter installed on a vehicle since there is no combustion. Thus, the catalytic materials are converted into an oxidizing atmosphere. As a result, NOx purification performance of the catalyst deteriorates, and eventually NOx is emitted when combustion restarts. The quantity of NOx in this period is relatively small. However, in case of increasing fuel cuts, emission problem could arise. Therefore, in order to meet the stringent regulation such as LEV III-SULEV20 or 30, the number of fuel cuts need to be limited. The problem is that this strategy leads to a disadvantage of fuel efficiency.
Technical Paper

Development of Ultra-Stable Cu-SCR Aftertreatment System for Advanced Lean NOx Control

2019-04-02
2019-01-0743
The integration of SCR catalyst into diesel-particulate filter (SDPF) may be one of most viable ways to meet upcoming stringent emission regulations with new test protocols such as Worldwide harmonized Light vehicles Test Cycles (WLTC) and Real Driving Emissions (RDE) requirements. The chabazite-structured SSZ-13-based catalysts enabled the wide implementation of urea-SCR technology for mobile applications due to their robust thermal stability up to 750°C compared to the thermally unstable ZSM-5-based technologies. However, the thermally stable Cu-SSZ-13 catalyst starts losing its initial activity with the increase of aging time at 850°C, where the SCR catalyst on SDPF can possibly be exposed during filter regeneration under a drop-to-idle (DTI) condition. Therefore, more durable SCR catalysts that survive under higher temperatures have been strongly desired in automotive industry. Recently, we found Cu-exchanged high silica LTA revealed an excellent hydrothermal stability.
Technical Paper

Smart Engine Control Strategy for the Fuel Efficiency Improvement via Understanding the Unique Behavior of TWC

2019-03-25
2019-01-1406
The worldwide fuel economy compliance level has been tightening, at the same time, LEV-III/Euro-6d/China-6/BS-6 regulations for NMOG and NOx emissions are being introduced or already effective. Therefore, intensive research effort has been conducted in order to improve the fuel efficiency of passenger cars and reduce exhaust emission. In response to these demands, turbocharged gasoline direct injection (TGDI) engine is being introduced for gasoline vehicles in consideration of fuel efficiency improvement, high output and driving performance compared to naturally aspirated (NA) engine. However, due to its larger thermal mass from the turbo hardware in the exhaust, it suffers from the cold-start emission. The main hazardous gases emitted from gasoline vehicles are CO, HC and NOx, and a three-way catalyst (TWC) is installed for the purification of these harmful emissions.
Technical Paper

A Study of the Half Order Modulation Control for Diesel Combustion Noise by Using Model Based Controller Design

2019-03-25
2019-01-1416
This model based investigation is carried out in order to control the half order modulation for diesel engines using by virtual calibration approach and proposes a feedback control strategy to mitigate cylinder to cylinder imbalance from asymmetric cylinders torque production. Combustion heat release analysis is performed on test data to understand the root cause of observed cylinder to cylinder pressure variations. The injected fuel variations are shown to cause the observed pressure variations between cylinders. A feedback control strategy based on measured crank shaft position is devised to control the half order modulation to balance the combustion pressure profile between cylinders. This control strategy is implemented in Simulink and is tested in closed-loop with the diesel engine model in AMESim. The closed-loop performance indicates that the half order modulation is considerably improved while having minimal impact on the fuel consumption.
Technical Paper

Development of Surfactant-Free Anti-Fogging Coating for Automotive Headlamps

2019-03-25
2019-01-1439
Recently, the design of automotive headlamps has become diversified and complicated according to customer needs. Hence, structural complexity of the headlamps has also increased. Complex structure of the headlamps inevitably causes a disturbance in air circulation. For this reason, inadvertent micro-sized water droplets, called fogging, are condensed on the inner surface of headlamp lens due to temperature difference between the inner and outer lens surfaces. To circumvent fogging inside of the headlamp lens, an anti-fogging coating is indispensable. Conventionally, diverse surfactants have been adopted as substantial material for the anti-fogging coating. However, the usage of the surfactants causes undesirable side effect such as water mark arising from vapor condensation, which is an important issue that must be fully resolved. In this study, we developed an innovative anti-fogging coating material without using conventional surfactant.
Technical Paper

The CAE Analysis of a Cylinder Head Water Jacket Design for Engine Cooling Optimization

2018-04-03
2018-01-1459
Hyundai's new engine is developed which optimize the cooling efficiency for knocking improvement and friction reduction. The cooling concepts for this purpose are 1) equalizing the temperature among cylinders by flow optimization, 2) cooling the required area intensively, 3) adopting ‘active flow control’ and 4) enlarging fuel economy at high speed range. In order to realize the cooling concept, 1) cross-flow, 2) compact water jacket & exhaust cooling, 3) flow control valve and 4) cylinder head with integrated exhaust manifold are considered. Improvement of knocking and friction reduction by increased cooling water temperature makes fuel efficiency possible. On the other hand, in order to strengthen the cooling around the combustion chamber and to reduce the deviation among the combustion chamber of cylinders, it is required to design the head water jacket shape accordingly.
Technical Paper

Development of Multi-Functioning Lean NOx Trap Catalysts for the On-board NH3 Generation

2018-04-03
2018-01-1430
Improved Lean NOx Trap (LNT) catalysts with enhanced NH3 generation feature were developed for the small diesel engine. The next generation LNT system needs to perform good NOx conversions over the wide temperature range including below 200°C for urban driving and above 400°C for motorway of real road driving. However, the extended use of BaO, a component of LNT known to be very effective for high temperature NOx storage, results in the decrease of low temperature NOx conversion due to the degradation of NO oxidation associating with sulfur over time. The improvement of the low-temperature LNT performance is a key requirement for the real driving emission control as the best operation temperature for urea-SCR is above ~250°C. In this study, our next generation LNT with new washcoat architecture has demonstrated improved NOx removal efficiencies under the wider operation temperature window than the current production technology.
Technical Paper

A Study of Low-Friction Road Estimation using an Artificial Neural-Network

2018-04-03
2018-01-0811
Road friction estimation algorithms had been studied for many years because it is very important factor for safety control and fuel efficiency of vehicle. But traditional solutions are hard to adapt in automotive industry because their performance is not sufficient enough and expensive to implement. Therefore, this paper proposes a road friction estimation algorithm based on a trained artificial neural-network which is low cost and robust. The suggested method doesn’t need expensive additional sensors such as optical or lidar sensor, also it shows better performance in real car environment compared to other algorithms based on vehicle dynamics. In this paper, we would describe this algorithm in detail and analyze the test results evaluated in real road conditions.
Technical Paper

A Study on the Method to Manage the Weight and Cost of a Vehicle by Adjusting the Parameters of Styling Profile

2018-04-03
2018-01-1025
Since the fuel efficiency of vehicle has become one of the big issues due to environmental pollution problems, many studies have been conducted on various methods such as improving powertrain performance and aerodynamic performance, reducing the weight of the vehicle and so on. There have been many new attempts to reduce weight but mostly about improving material property. In the case of vehicles sharing the same platform, the weight and cost of vehicle are mainly changed by the exterior styling. But, there is no solution to control the exterior styling in terms of the weight and cost of vehicle, yet. The purpose of this study is to find the way to save the weight and cost of vehicle while achieving the various performance and requirements of vehicle (safety, aerodynamics, driver’s visibility and so on) from exterior styling point of view. We focused on the weight difference of the vehicles that shared the platform and were same overall dimensions.
Technical Paper

Development New Organic Composite Materials with Excellent Long-Term High-Temperature Durability and Reliability for Automotive Parts

2018-04-03
2018-01-0151
In recent years, the emerging technology competitions in automotive industry are improving engine efficiency and electronizing for coping with stringent fuel-economy regulations. However, fuel-economy technologies such as engine down-sizing and numerous electronic parts entrust burden plastic materials acing as mainly electric insulation and housing to have to be higher performance, especially temperature endurance. Engineering plastics (EPs) have critical limitations in terms of degradation by heat. Heat-resisting additives in EP are generally used to be anti-degradation as activating non-radical decomposition of peroxide. However, it could not be effective way to impede the degradation in long term heat aging over 1,000 hours at high temperature above 180 °C. In this study, we suggested the new solution called ‘shield effect’ that is purposeful oxidation at the surface and local crystallization of EP to stop prevent penetrating oxygen to inside of that.
Technical Paper

A Development of Aluminum EGR Cooler for Weight Reduction and Fuel Economy

2018-04-03
2018-01-0102
As environmental problems such as global warming are emerging, regulations on automobile exhaust gas are strengthened and various exhaust gas reduction technologies are being developed in various countries in order to satisfy exhaust emission regulations. Exhaust gas recirculation (EGR) technology is a very effective way to reduce nitrogen oxides (NOx) at high combustion temperatures by using EGR coolers to lower the combustion temperature. This EGR cooler has been mass-produced in stainless steel, but it is expensive and heavy. Recently, high efficiency and compactness are required for the EGR cooler to meet the new emission regulation. If aluminum material is applied to the EGR cooler, heat transfer efficiency and light weight can be improved due to high heat transfer coefficient of aluminum compared to conventional stainless steel, but durability is insufficient. Therefore, the aluminum EGR cooler has been developed to enhance performance and durability.
Technical Paper

A Development of Fuel Saving Driving Technique for Parallel HEV

2018-04-03
2018-01-1006
This paper examines the effect of pulse-and-glide (PnG) driving strategies on the fuel efficiency when applied on parallel HEVs. Several PnG strategies are proposed, and these include the electrical, mechanical, and combined PnG strategies. The electrical PnG strategy denotes the hybrid powertrain control tactics in which the battery is charged or discharged according to the power demanded while maintaining the constant vehicle speed. On the other hand, the mechanical PnG strategy denotes the powertrain control tactics in which the vehicle accelerates or decelerates according to the power load while minimizing the battery usage. The combined PnG strategy involves both electrical and mechanical strategies to find a balanced point in between them. Here, a tradeoff relationship between the fuel efficiency and the vehicle drivability related to the tracking performance of the desired target speed is revealed.
Technical Paper

Development of High Efficiency Gasoline Engine with Thermal Efficiency over 42%

2017-10-08
2017-01-2229
The maximum thermal efficiency of gasoline engine has been improving and recently the maximum of 40% has been achieved. In this study, the potential of further improvement on engine thermal efficiency over 40% was investigated. The effects of engine parameters on the engine thermal efficiency were evaluated while the optimization of parameters was implemented. Parameters tested in this study were compression ratio, tumble ratio, twin spark configuration, EGR rate, In/Ex cam shaft duration and component friction. Effects of each parameter on fuel consumption reduction were discussed with experimental results. For the engine optimization, compression ratio was found to be 14, at which the best BSFC without knock and combustion phasing retardation near sweet spot area was showed. Highly diluted combustion was applied with high EGR rate up to 35% for the knock mitigation.
Technical Paper

Effect of Injector Nozzle Hole Geometry on Particulate Emissions in a Downsized Direct Injection Gasoline Engine

2017-09-04
2017-24-0111
In this study, the effect of the nozzle tip geometry on the nozzle tip wetting and particulate emissions was investigated. Various designs for the injector nozzle hole were newly developed for this study, focusing on the step hole geometry to reduce the nozzle tip wetting. The laser induced fluorescence technique was applied to evaluate the fuel wetting on the nozzle tip. A vehicle test and an emissions measurement in a Chassi-Dynamo were performed to investigate the particulate emission characteristics for injector nozzle designs. In addition, the in-cylinder combustion light signal measurement by the optical fiber sensor was conducted to observe diffusion combustion behavior during the vehicle test. Results showed that the step hole surface area is strongly related to nozzle tip wetting and particulate emissions characteristics. Injectors without the step hole and with a smaller step hole geometry showed significant reduction of nozzle tip wetting and number of particulate emissions.
Technical Paper

A Study of the Auxiliary Belt Drive System for Actual Fuel Saving

2017-03-28
2017-01-0898
The engine indicated torque is not delivered entirely to the wheels, because it is lowered by losses, such as the pumping, mechanical friction and front auxiliary power consumption. The front auxiliary belt drive system is a big power consumer-fueling and operating the various accessory devices, such as air conditioning compressor, electric alternator, and power steering pump. The standard fuel economy test does not consider the auxiliary driving torque when it is activated during the actual driving condition and it is considered a five-cycle correction factor only. Therefore, research on improving the front end auxiliary drive (FEAD) system is still relevant in the immediate future, particularly regarding the air conditioning compressor and the electric alternator. An exertion to minimize the auxiliary loss is much smaller than the sustained effort required to reduce engine friction loss.
Journal Article

A Development of Energy Management System with Semi-Transparent Solar Roof and Off-Cycle Credit Test Methodology for Solar Power Assisted Automobile.

2017-03-28
2017-01-0388
CO2 emission is more serious in recent years and automobile manufacturers are interested in developing technologies to reduce CO2 emissions. Among various environmental-technologies, the use of solar roof as an electric energy source has been studied extensively. For example, in order to reduce the cabin ambient temperature, automotive manufacturers offer the option of mounting a solar cell on the roof of the vehicle [1]. In this paper, we introduce the semi-transparent solar cell mounted on a curved roof glass and we propose a solar energy management system to efficiently integrate the electricity generated from the solar roof into internal combustion engine (ICE) vehicles. In order to achieve a high efficiency solar system in different driving, we improve the usable power other than peak power of solar roof. Peak power or rated power is measured power (W) in standard test condition (@ 25°C, light intensity of 1000W/m2(=1Sun)).
Technical Paper

Study on Characteristics of Motor Output Power Depending on Current Sensor Response in Eco-Friendly Vehicles

2017-03-28
2017-01-1222
The current sensor for motor control is one of the main components in inverters for eco-friendly vehicles. Recently, as the higher performance of torque control has become required, the current sensor measurement error and accuracy of motor controls have become more significant. Since the response time of the sensor affects the motor output power, the response delay of the sensor causes measurement errors of the current. Accordingly, the voltage vector changes, and a motor output power deviation occurs. In the case of the large response delay of the sensor, as motor speed increases, then difference between motoring and generating output power becomes larger and larger. This results in the deterioration of power performance in high-speed operation. The deviation of the voltage vector magnitude is the main cause of motor output power deviation and imbalance through the simulation.
Technical Paper

Influence of the Injector Geometry at 250 MPa Injection in a Light-Duty Diesel Engine

2017-03-28
2017-01-0693
This paper investigated the influence of the injector nozzle geometry on fuel consumption and exhaust emission characteristics of a light-duty diesel engine with 250 MPa injection. The engine used for the experiment was the 0.4L single-cylinder compression ignition engine. The diesel fuel injection equipment was operated under 250MPa injection pressure. Three injectors with nozzle hole number of 8 to 10 were compared. As the nozzle number of the injector increased, the orifice diameter decreased 105 μm to 95 μm. The ignition delay was shorter with larger nozzle number and smaller orifice diameter. Without EGR, the particulate matter(PM) emission was lower with larger nozzle hole number. This result shows that the atomization of the fuel was improved with the smaller orifice diameter and the fuel spray area was kept same with larger nozzle number. However, the NOx-PM trade-offs of three injectors were similar at higher EGR rate and higher injection pressure.
Technical Paper

Transient Nonlinear Full-Vehicle Vibration Analysis

2017-03-28
2017-01-1553
This paper presents a transient vibration analysis of a nonlinear full-vehicle. The full-vehicle model consists of a powertrain, a trimmed body, a drive line, and front and rear suspensions with tires. It is driven by combustion forces and runs on a road surface. By performing time-domain simulation, it is possible to capture nonlinear behavior of a vehicle such as preload due to gravitational force, large deformation, and material nonlinearity which cannot be properly treated in the conventional steady state analysis. In constructing a full-vehicle, validation process is essential. Validation process is applied with respect to the assembling sequence. The validation starts with component levels such as tires, springs, shock absorbers, and a powertrain, and then the full-vehicle model is constructed. Model validation is done in two aspects; one is model accuracy and the other is model efficiency.
Technical Paper

Closed-Loop Control Method for Monitoring and Improving the Diesel Combustion Noise

2016-06-15
2016-01-1770
This paper presents two closed-loop control methods for monitoring and improving the combustion behavior and the combustion noise on two 4-cylinder diesel engines, in which an in-cylinder pressure and an accelerometer transducer are used to monitor and control them. Combustion processes are developed to satisfy the stricter and stricter regulations on emissions and fuel consumption. These combustion processes are influenced by the factors such as engine durability, driving conditions, environmental influences and fuel properties. Combustion noise could be increased by these factors and is detrimental to interior sound quality. Therefore, it is necessary to develop robust combustion behaviors and combustion noise. For this situation, we have developed two closed-loop control methods. Firstly, a method using in-cylinder pressure data was developed for monitoring and improving the combustion noise of a 1.7L engine. A new index using the values calculated from the data was proposed.
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