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Technical Paper

A Study on the Solid Ammonium SCR System for Control of Diesel NOx Emissions

One of most effective NOx control technology of modern diesel engines is SCR with ammonia. Current NOx reduction systems are designed to use a solution of urea dissolved in water as a source of ammonia. However, the liquid urea systems have technical difficulties, such as a freezing point below −11°C and solid deposit formation in the exhaust temperature below 200°C. The objective of this study is to investigate the possibility of a new ammonia generation system that uses low-cost solid ammonium salt, such as solid urea and ammonium carbonate. The result shows that ammonium carbonate is more suitable than solid urea because of low decomposition temperature and no change to the other ammonium salt during the decomposition process. This paper also shows the NOx reduction capability of the new ammonia delivery system that uses ammonium carbonate.
Technical Paper

A Study on the Sound Transmission Loss of Split HVAC for Electric Vehicles

Generally, the HVAC system of a vehicle is composed of Blower unit assembly and Heater unit assembly, and is located on the driver’s side of the dash panel. However, electric vehicles have far fewer parts than conventional internal combustion engine vehicles, so electric vehicles have large space in the engine room. This allows HVAC, which occupies large volume in the interior side, to be pushed in the direction of the engine room altogether, or by placing a part inside the engine room to make a slim cockpit and expand the interior space. However, this new structure, called the Split HVAC System, is mounted through the dash, allowing noise to pass through relatively easily. Since this adversely affects the NVH of an electric vehicle, it needs to be developed in terms of noise transmission. Therefore, in this paper, a study was conducted to predict the sound transmission loss of Split HVAC through an analytical method.
Technical Paper

A Study on the Strategy and Implementing Technology for the Development of Luxurious Driving Sound

This paper describes a systematic approach to the development of a luxurious driving sound. In the first step, the luxurious sound is conceptualized through jury test, factor analysis and regression analysis. From the results, the main factors and the correlation equation for the luxurious sound are extracted. Also, customer's preference for the luxurious sound is investigated from the customer clinic. In the second step, three core axes and the detailed indices for luxurious sound are defined and quantified. These core axes are a dynamic sound character, a sound balance and a sound harmony. These core axes are also composed of detailed indices and quantified by guide lines. In the third step, each contribution of the sub-systems for sound quality is identified and the target values and methods for implementing the luxurious sound are suggested. In this process, noise path analysis and the customer's preference in each region are considered.
Technical Paper

A Study on the Strength of Catalytic Converter Ultra Thin Wall Substrates

Application of Ultra Thin Wall (UTW) ceramic substrates in the catalytic converter system requires the canner and component manufacturers to better understand the root cause and physics behind substrate breakage during the canning process. For this purpose, a ceramic substrate strength study for shoebox design has been conducted within Visteon Corporation. Computer Numerical Control (CNC) machined top and bottom fixtures, with identical inner surfaces as shoebox converter upper and lower shells, were used to crush mat wrapped substrates. Thin film pressure sensor technology enables the recording of substrate surface pressure during the compression process. Shell rib, washcoat, canning speed and cell density effects on substrate failure have been experimentally investigated. The development of a mathematical model helps to identify a better indicator to evaluate the substrate strength in the canning process and establish the strength for uncoated & coated substrates.
Technical Paper

A Study on the Structural Design and Reliability of Cylinder Head for Vehicle Engines

For reducing the heat rejection and enhancing the cylinder head's performance of enduring the thermal loads, the LHR cylinder head with a ceramic insulating layer is presented in this paper. The ceramic insulating layer, with the thickness of 0.0 mm, 0.7mm, 1.0mm and 1.5mm, is adopted respectively to illustrate the effect of thickness of the ceramic layer on the amount of the heat transfer of the cylinder head. Computed results show that the amount of the heat transfer decrease with the growth of the thickness of the ceramic layer. The three-dimensional FEA is used to calculate the cylinder head's mechanical-thermal comprehensive stresses. According to the FEA results, the stresses of characteristic points of the cylinder head with the heat-insulating layer become larger than those of the non-LHR cylinder head. Then, numerical analyses based on the stress-strength interference are performed to evaluate the cylinder head reliability with different thickness ceramic layer.
Technical Paper

A Study on the Surface Temperature of Rotary Lip Seals

This paper presents a measuring technique, a test result and a finite element analysis result of a surface temperature of rotary lip seals. A thermocouple embedded in the surface of a shaft and radio transmission systems provide wireless measurement for the temperature of the rotary shaft, which is driven up to 6000 rpm. Relationships between shaft temperature, lip temperature and sliding speed were shown. Torque of PTFE coated seals is about 23 % lower than that of conventional seals at 22 m/s. At that time, the shaft temperature of PTFE coated seals is about 7 K lower than that of conventional seals. And, Lip temperature of PTFE coated seals is about 1 K lower. In the analysis result, high temperature part of the shaft is larger than that of the lip, that is, heat is concentrated in the sealing edge of the lip. Temperature rise of the analysis result is consistent with those of the test result.
Technical Paper

A Study on the Tangential Vibration of the Steering Wheel of Passenger Car

The tendency of high speed and low-weight of passenger car may result in the bad feeling of ride comfort and controllability so that new design concept and technology has been required to solve the problems. Especially, the tangential vibration of the steering wheel makes the driver uncomfortable seriously at high speed [1-5]. So to trace the origin, we use T.L.H. coordinate which is a standard in vehicle design, besides the steering wheel system and the frame are modeled by 20 D.O.F. to estimate dynamic characteristics of new cars with possible changes of the locations of linkages and material properties. Generally, the vehicle frame is considered as a rigid body in the vibration analysis of a vehicle. In this study, however, we have modeled the frame as a elastic body. Moreover, the effects of the dry friction in ball joint and tie-rod, king pin inclination and the side slip of the tire are included in the present analysis to supply design parameters required for new vehicles.
Technical Paper

A Study on the Thermal Characteristics According to Input Voltage Variation in Micro Chip Hydrogen Sensor for Fuel Cell Electric Vehicle

Recently, energy conversion system has been proposed the use of a hydrogen which is a typical low carbon and eco-friendly energy. The hydrogen energy have demerits for storage and movement because hydrogen gas have a big diffusion characteristic, even if hydrogen energy is a eco-friendly energy. Therefore, hydrogen leakage sensing system is necessarily applied and required for high sensing performance. In this study, we conducted to determine the design parameters for the micro chip hydrogen sensor with optimized sensing conditions under the thermal characteristics. The thermal characteristics on input voltage variation was studied for correlation analysis of current, consumption power and heater temperature according to the input voltage variation from 1.0 voltage to 10.0 voltage every 0.5 voltage. The heater resistance was higher, the heat generation temperature was lower. The heat generation temperature depended on current.
Technical Paper

A Study on the Thermal Interface Mechanisms of Natural Fiber/Fillers and Allotrope-Based Polymers

Composites of polymers reinforced with synthetic/natural fibers are mainly used in engineering sectors such as automobiles, aerospace, and in household appliances due to their abrasion resistance, high toughness, strength, and high specific modulus. The purpose of this research is to provide an overview of fiber-matrix interfaces and interface mechanism that leads to enhanced properties. This article investigates how natural/synthetic fibers, mineral based-materials and additional allotropic materials work rapidly and effectively across interfaces.
Technical Paper

A Study on the Time and Space Resolved Measurement of Flame Temperature and Soot Concentration in a D. I. Diesel Engine by the Two-Color Method

The two-color method regarding the visible wavelength radiation from soot particles in flames was closely studied in order to establish it as a measuring technique of the flame temperature and soot concentration in diesel engines. The accuracy of the temperature calibration of the measuring equipment was assured by a newly developed high temperature black body furnace and a standard tungsten lamp. The emissivity of diesel flames, which is the most important value in this method, was investigated through both the spectroscopic analysis of soot sampled from a diesel flame and the comparative measurements between the two-color method and the emission-absorption method. The examined two-color method was applied to a direct injection diesel engine. The time and space resolved values of temperature and soot concentration were obtained for the first time.
Technical Paper

A Study on the Torque Capacity of Belt CVTs for 2.0-Liter and 3.5-Liter Front-Drive Cars

An actual-size belt box tester was used to measure the slip characteristics of 2.0-liter and 3.5-liter class CVTs under a condition of their lowest pulley ratio. The measured results were then used to calculate and compare the element-pulley friction characteristics of both CVTs and the active arc of the element compressive force generated on their primary pulley. A 3-D finite element model, capable of analyzing the 3-D dynamic behavior of the belt and pulleys and stress, was applied to compare the band tensile force and element PV values of the two CVTs. As a result, it was found that the 3.5-liter class CVT has approximately the same percentage of torque capacity allowance and strength limits as the 2.0-liter class unit.
Technical Paper

A Study on the Torque Capacity of a Metal Pushing V-Belt for CVTs

The mechanism causing the micro slip characteristic of a metal CVT belt during torque transmission was analyzed, focusing on the gap distribution between the elements. It was hypothesized that gaps between the elements cause slip to occur between the elements and the pulleys when the belt is squeezed between the two halves of the pulleys, and the slip ratio was calculated theoretically on that assumption. The μ-v (friction coefficient versus sliding velocity) characteristic between the elements and the pulleys was measured and the results were used in calculating the slip ratio. As a result, a simulation procedure was developed for predicting the slip-limit torque of the belt on the basis of calculations. The slip ratio found by simulation and the calculated slip-limit torque showed good quantitative agreement with the experimental data, thereby confirming the validity of the simulation procedure.
Technical Paper

A Study on the Transfer Path Analysis of Brake Creep Groan Noise

Creep groan noise occurs in a just moving vehicle by the simultaneous application of torque to the wheel and the gradual release of brake pressure in-vehicle. It is the low frequency noise giving the driver a very uncomfortable feeling. It is caused by the stick-sleep phenomenon at the lining and disc interface. Recently, the field claim of low frequency creep groan has increased. There are a lot of efforts to improve creep groan noise by means of modification of lining material. In this paper, Transfer path of creep groan noise was analyzed through ODS and TPA. Additionally the correlation between Source (Brake torque variation, Brake vibration) and Creep Groan Sound level was discussed. Finally countermeasure to Creep Groan noise was suggested.
Technical Paper

A Study on the Transient Characteristics of Automatic Transmission with Detailed Dynamic Modeling

Transient characteristics during gear ratio change including the disturbance of output torque have been important issues in the study of passenger car automatic transmission. In this paper, to investigate the transient characteristics during gear ratio change, a detailed dynamic model of the power transmission system of a passenger car focused on the automatic transmission was proposed and the governing dynamic equations were derived and solved. The results of simulation showed good agreements with the experimental data. It was proved that the suggested dynamic model is very useful to analyze the phenomena occurred during the speed ratio change.
Technical Paper

A Study on the Transient Knock Control in a Spark-Ignition Engine

In this study, an investigation of the transient knock characteristics in a four cylinder DOHC spark-ignition engine has been carried out. We simulated the behavior of an engine during the rapid acceleration of a car using an eddy current type dynamometer. In a commercial ECU, spark timing was retarded from the steady state value during rapid acceleration to prevent uncomfortable feeling and knock. Knock usually occurred just after the start of acceleration when spark timing was advanced from the value set by the commercial ECU. We found that air/fuel ratio was about stoichiometric for a knocking cycle. Transient knock control logic was developed which used air/fuel ratio information of an O2 sensor as a control input. Torque was improved during rapid acceleration by using the transient knock control.
Technical Paper

A Study on the Tribological Performance of an Organic Cadmium Compound as a Lubricant Additive

An oil-soluble cadmium dipropyldithiophosphate additive was synthesized. A four-ball wear tester was used to evaluate the tribological performance of the additive in a mineral oil and lubricant grease under different loads and compared with some commercial additives. The results show that it exhibits excellent antiwear and load-carrying capacities, better than commercial additives. In comparison Scanning electron microscopy (SEM) with Energy dispersive X-ray (EDX), and X-ray photoelectron spectrometer (XPS) were used to investigate the topography, and chemical composition of the rubbing surface. Smooth and light topography of the wear scar confirms that the additive showed good antiwear characteristics.
Technical Paper

A Study on the Turning Characteristics and Optimization of MOS2p and SiCp-Reinforced Al-Si10Mg Metal Matrix Composites

In the fabrication of parts in auto and aero segments, the use of ceramic (SiCp, Al2O3p) reinforces aluminum alloy found to be increased than that of steel and cast iron. This matrix-reinforced alloy has a high strength to weight ratio along with higher modulus and hardness, the lower thermal coefficient of expansion, and improved tribological properties. To this extent, this paper investigates the turning characteristics and optimization study of newly developed metal matrix composites by the addition of both hard ceramic SiCp and soft stable lubricant molybdenum disulfide (MoS2p). The samples such as Sample 1: AlSi10Mg/3SiCp, Sample 2: AlSi10Mg/2MoS2p and Sample 3: AlSi10Mg/3SiCp /2MoS2p are prepared using the automated stir-casting machine. The particles are observed to be uniformly distributed in the composite. After density and hardness measurement, the samples are subjected to machining, and the responses are optimized by using response surface method.
Technical Paper

A Study on the Urea-Water Solution Dosing Strategy by NO/NOX Ratio of DeNOX SCR System

In this study, SCR system is employed to selectively reduce NOX that is a major cause of environmental pollution from diesel engines. In particular, this paper focuses on urea injection strategies dependent on NO/ NOX ratio. An injection control algorithm is developed based on the chemical ratio between the amount of engine out NOX data obtained from Engine Management System (EMS) and the amount of NH3. Therefore, in order to decide the amount of injection quantity, the NO/NOX ratio from the engine out NOX should be considered in order to minimize NH3 slip while maximizing NOX reduction. Experiments are conducted with a 2.2-liter diesel engine for passenger vehicles with Diesel Oxidation Catalyst (DOC) and Diesel Particle Filter (DPF). Real time control, using Pulse Width Modulation (PWM) duty ratio for dosing module and supply module, is performed by real time computer with its injection control algorithm developed in the Matlab Simulink environment.
Technical Paper

A Study on the Use of Combustion Phase Indicators for MBT Spark Timing on a Bi-Fuel Engine

The performance of a spark ignition engine strongly depends on the phase of the combustion process with respect to piston motion, and hence on the spark advance; this fundamental parameter is actually controlled in open-loop by means of maps drawn up on the test bench and stored in the Electronic Control Unit (ECU). Bi-fuel engines (e.g. running either on gasoline or on natural gas) require a double mapping process in order to obtain a spark timing map for each of the fuels. This map based open-loop control however does not assure to run the engine always with the best spark timing, which can be influenced by many factors, like ambient condition of pressure, temperature and humidity, fuel properties, engine wear. A feedback control instead can maintain the spark advance at its optimal value apart from operative and boundary conditions, so as to gain the best performance (or minimum fuel consumption).
Technical Paper

A Study on the Use of Intake Flow Path Modification to Reduce Methane Slip of a Natural Gas-Diesel Dual-Fuel Engine

Use of natural gas-diesel dual-fuel (NDDF) combustion in compression ignition engines is a method of reducing the net greenhouse gas (GHG) and particulate matter (PM) emissions of these engines. Compressed natural gas (NG) is injected into the intake manifold of the engine and the air-NG mixture is ignited by a direct injection of diesel in the cylinder. One of the main challenges with NDDF combustion is the methane (primary component of NG) slip at low and medium loads, which reduces the engine efficiency and offsets the advantage of lower carbon dioxide emissions of the NG combustion. In order to address this issue, an intake manifold insert is devised with the objective to alter the intake flow profile into the engine and ultimately reduce the methane slip. This is a novel strategy for an NDDF engine since modifying the in-cylinder flow profile can intensify the mixing between diesel and air-NG mixture in order to improve the NG utilization in the cylinder.