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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Automotive Engineers
Editor in Chief :
Volume & Issues
Volume 16, Issue 6 - Nov 2008
Volume 16, Issue 5 - Sep 2008
Volume 16, Issue 4 - Jul 2008
Volume 16, Issue 3 - May 2008
Volume 16, Issue 2 - Mar 2008
Volume 16, Issue 1 - Feb 2008
Selecting the target year
The Effect of Compressive Residual Stress according to Corrosion Fatigue Life of Automobile Suspension Material
Ki, Woo-Tae ; Park, Sung-Mo ; Moon, Kwang-Seok ; Park, Kyeong-Dong ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 1~7
A study of new materials that are light-weight, high in strength has become vital to the machinery of auto industries. But then, there are a lot of problems with developing such materials that require expensive tools, and a great deal of time and effort. Therefore, the improvement of fatigue strength and fatigue life are mainly focused on by adopting residual stress. And Influence of corrosive condition for corrosion fatigue crack was investigated, after immersing in 3.5%NaCl,
. The immersion period was performed for 365days. The compressive residual stress was imposed on the surface according to each shot velocity based on shot peening, which is the method of improving fatigue life and strength. Fatigue life shows more improvement in the shot peened material than in the un peened material in corrosion conditions. The threshold stress intensity factor range was decreased in corrosion environments over ambient. Compressive residual stress of surface on the Shot-peen processed operate resistance force of fatigue crack propagation. The fatigue crack growth rate of the Shot-peened material was lower than that of the un peened material. Also m, fatigue crack growth exponent and number of cycle of the shot peened material was higher than that of the un peened material. That is concluded from effect of da/dN.
A Study on Couplant Medium Improvement for Ultrasonic Inspection System with Water Immersion to Detect Weld Defects
Jung, Dal-Woo ; Choi, Nak-Sam ; Park, Yong-Bae ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 8~14
For nondestructive inspection of electron beam (EB) welding part in automotive power transmission assembly, a pulse-echo ultrasonic testing apparatus in water immersion has been applied using the ultrasonic waves with a frequency of 10MHz. However various problems have appeared during the ultrasonic inspection, which led to some significant mistakes in automatic quality evaluation of the welding parts. Experimental study showed that the state of water couplant medium containing some amount of contaminants, rusts and anti-corrosion agents had considerable influences on the reduction of ultrasonic amplitudes during wave propagation. The amplitude reduction depending on the coupling medium state could bring about some mis-diagnoses for defects in the welding parts. The results proposed that for a reliable inspection of defects in welds the state of water medium should be kept in about 15 volume fractions (vol.%) of anti-corrosion agents and in minimized contaminants.
The Study on PRAT Performance due to Tire Pattern Shapes using Steady State Rolling Analysis Method
Sung, Ki-Deug ; Park, Hyun-Man ; Koo, Byong-Kook ; Cho, Choon-Tack ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 15~21
It is generally known that the PRAT(Plysteer Residual Aligning Torque) is one of indicating a performance factors of a tire for assessing the vehicle pull, also tire pattern shape, which means lateral groove angle, is very important tire design factor in relation to the PRAT. Lateral grooves of tire pattern are widely divided into center and shoulder parts. So, this paper has studied the correlation between the PRAT and their lateral groove angles using FEM. Especially, the steady state rolling analysis among tire rolling analysis methods has been used for the PRAT performance study. Firstly, analysis result data have been compared with the experimental data to validate FE analysis for PRAT. Next, the PRAT due to the lateral groove angle about PCR(Passenger Car Radial) tire and SUV tire has been analyzed. The tendency of the PRAT due to the lateral groove angles can be used as a guide line for the tire design in relation to vehicle pull.
A Numerical Analysis of Flow Characteristics and Oil Separation Performance for Cyclone Oil Separator Designs
Cho, Yong-Seok ; Lee, Seang-Wock ; Woo, Keun-Sup ; Yoon, Yu-Bin ; Park, Young-Joon ; Lee, Dug-Young ; Kim, Hyun-Chul ; Na, Byung-Chul ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 22~28
A closed type crankcase ventilation system has been adopted to engines to prevent emission of blow-by gas to atmosphere. In the early closed type crankcase ventilation system, blow-by gas which contains engine lubricating oil is re-circulated into the intake system. The blow-by gas containing oil mist leads to increased harmful emissions and engine problems. To reduce loss of the engine oil, a highly-efficient oil separation device is required. Principle of a cyclone oil separator is to utilize centrifugal force in the separator and, therefore, oil separator designs depend on rotational flow which causes the centrifugal force. In this paper, flow characteristics and oil separation performances for cyclone type designs are calculated with CFD methodology. In the CFD model, oil particle was injected on a inlet surface with Rosin-Rammler distribution and uniform distribution. The major design parameters considered in the analysis model are inlet area, cone length and outlet depth of the oil separator. As results, reducing inlet area and increasing cone length increase oil separation performance. Changes in outlet depth could avoid interference between rotational flow and outlet flow in the cyclone oil separator.
Numerical Analysis of Effective Turbocharger and Baffle on Flow Field in Warm-up Catalyst for Diesel Vehicles
Choi, Byung-Chul ; Juhng, Woo-Nam ; Kang, Chang-Hyuk ; Wi, Dae-Woong ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 29~36
Diesel vehicle is growing in importance in light-duty sector as a way of reducing greenhouse gases due to improved fuel economy. Carbon monoxide, gas-phase hydrocarbon and organic fraction of diesel particulates can be oxidized to harmless products using a diesel warm-up catalyst (WCC). This study investigated the effect of a turbocharger and a baffle on flow fields and temperature distributions in the WCC for Diesel vehicles by a numerical analysis. In the case of the WCC with the turbocharger, velocity vectors and temperatures of inlet of the WCC have the relatively homogeneous distributions by the swirl generated from the turbocharger. Velocity vectors and temperatures of inlet of the WCC with the turbocharger and the baffle have the improved distributions in homogeneity compared with the case of the WCC without the baffle. The homogeneous flow field and the temperature distribution in the WCC may contribute to improve the conversion performance of the catalysts.
An Experimental Study on the Durability Test for PEM Fuel Cell Turbo-blower
Lee, Yong-Bok ; Lee, Hee-Sub ; Chung, Jin-Taek ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 37~43
The durability test of turbo-blower for PEM fuel cell is very important process of BOP development. It is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the air supply system to increase the reliability and to reduce the lifetime cost. In this study, turbo-blower supported by oil-free bearing is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. The impeller of blower was adopted mixed type of centrifugal and axial. So, it has several advantages for variable operating condition. The turbo-blower test results show maximum parasitic power levels below 1.67kW with the 30,000 rpm rotating speed, the flow rate of air has maximum 163SCFM(@PR1.1). For proper application of FCV, these have to durability test. This paper describes the experiment for confirming endurance and stability of the turbo-blower for 500 hours.
A Study of the Fuel Economy Improvement of a Heavy Duty in Commercial Vehicle(I)
Lyu, Myung-Seok ; Doo, Byung-Mann ; Ku, Young-Gon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 44~48
This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.
Effect of Primary Nozzle Configuration on the Flow and Transfer Characteristics in an Ejector System for Pellet Transfer
Kim, Keum-Kyu ; Kim, Eui-Soo ; Kang, Shin-Myoung ; Lee, Jee-Keun ; Rho, Byung-Joon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 49~59
The effects of design parameters on the pellet transport rate in the ejector system which is widely used in the production processes of automotive parts were investigated experimentally. The primary nozzle geometry, the area ratio (R) of nozzle exit cross-sectional area to mixing chamber cross-sectional area and the distance (S) from primary nozzle exit to mixing chamber entrance were considered as the design parameters. The area ratios of the primary nozzle were varied from R=0.10 to R=0.25, 0.30, 0.40 and 0.55. The primary nozzle was positioned at the non-dimensional distance (S/D) of 1.30, 1.87, 2.44, 3.00 and 3.75, normalized using the mixing chamber diameter (D). The design parameters were determined to run with high efficiency by measuring the pellets transport rate. The geometry and the area ratio (R) of the primary nozzle had an effect on the pellet transport rate of the ejector system, and the area ratio of R=0.3 was carefully selected after taking the minimum fluidization velocity and transport rate of applied pellets into account. The higher pellet transport rate with the variation of the distance (S/D) was observed at S/D of 2.44.
De-NOx Characteristics for Cu-ZSM5/Alumina Beads Catalyst Filter in Urea-SCR System
Jang, Young-Sang ; Shin, Young-Seop ; Lee, Byoung-Jun ; Park, Jai-Koo ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 60~67
The catalytic filter of Cu-ZSM5/alumina beads was considered to reduce NOx in the urea SCR system. Catalytic support of porous alumina beads with mean pore size
were prepared using foaming and gel-casting method. The Cu-ZSM5 catalysts were coated on the supporting alumina beads using
by ion exchange method. After a washcoating process was applied to coat 10w% Cu-ZSM5 on porous alumina bead, coating layer was estimated
in thickness. The characterization and the feasibility as a catalytic supports were investigated. And the NOx conversion test in Cu-ZSM5/Alumina Beads filter system was conducted by using Urea as reductants under laboratory test. The NOx conversion was increased as size and porosity of beads and observed more than 95% excellent NOx conversion above
The Effect of an Oxidation Precatalyst on the
-SCR Process in Diesel Exhaust
Jung, Seung-Chai ; Yoon, Woong-Sup ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 68~76
-SCR in conjunction with the effective oxidation precatalyst was analytically investigated. Physicochemical processes in regard to
reduction and catalytic NO-
conversion are formulated with detailed descriptions on the commanding reactions. A unified model is correctly validated with experimental data in terms of extents of
reduction by SCR and NO-
conversion by DOC. The present deterministic model based on the rate expressions of Langmuir-Hinshelwood reaction scheme finds a conversion extent directly. A series of numerical experiments concomitant with parametric analysis of the
reduction was conducted.
reduction is promoted in proportion to DOC volume ar lower temperatures and an opposite holds at lower space velocity and intermediate temperatures.
conversion is weakly correlated to the space velocity and the DOC volume at higher exhaust temperature. In DOC-SCR system, the
reduction efficiency depends on the
Ride Performance Evaluation of a Heavy Truck Semi-active Cabin Air Suspension System
Lee, Ji-Sun ; Choi, Gyoo-Jae ; Lee, Kwang-Heon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 77~83
Semi-active cabin air suspension system improves driver's comfort by controlling the damping characteristics in accordance with driving situation. For the driver's comfort evaluation, test procedure has the two methodologies which are filed test and lab test. A field test method has a drawback. It requires a lot of time and money on repetitive test, due to the sensitivity of field test. On the other hand, the test with six axes simulation table at laboratory can obtain the repeatability of test, better than the field test method. In this paper, the procedures of ride performance test and control logic tuning with the table are presented. Drive files of the table can be represented with the almost same input condition as field test data. According to the result from the comparative test using six axes simulation table between passive and semi-active system by making ECU logic tuning, the RMS acceleration of semi-active cabin air suspension system was reduced by 29.6% compared with passive system.
Emission Characteristics of GTL(Gas to Liquid) Fuel in Diesel Engine
Lee, Yong-Gyu ; Moon, Gun-Feel ; Choi, Kyo-Nam ; Jeong, Dong-Soo ; Kim, Byoung-Jun ; Cha, Kyung-Ok ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 84~91
Due to increasing need for better emission characteristics and lower fuel consumption rate in automotive engines, alternative fuels are drawing more attentions recently. The GTL (gas to liquid) is the one of most favored candidates. In this study, emission characteristics are compared between diesel and GTL fuel in commercial 2.0 liter diesel engine and vehicle with CRDi(Common Rail Direct injection) system. The effects of injection timings on emission and fuel consumption rate are compared at various engine speeds and loads. Noticeable reduction in HC, CO and PM emissions are observed due to higher cetane number and low sulfur and aromatic contents in GTL. On the trade-off curve of NOx and PM(Particulate matter) GTL showed much more benefits than diesel, where about 30% of PM mass decreased at the same operating conditions. On CVS 75 mode test in vehicle, GTL showed an excellent emission enhancement, in which 50% of HC, 21% of PM, and 12% of NOx engine-out emissions are decreased compared to ULSD(Ultra low sulfur diesel) fuel.
A Study on the Signal Processing Method for the Hall Sensorless Position Control of ETC Control System using a BLDC Motor
Lee, Sang-Hun ; Lee, Seon-Bong ; Park, Cheol-Hu ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 92~99
This paper describes an signal processing method for the hall sensorless position control of ETC control system using a BLDC motor. The proposed ETC control system, which is mainly consisted of a BLDC motor, a throttle plate, a return spring and reduction gear, has a position sensor with an analog voltage output on the throttle valve instead of BLDC motor for detecting rotor position of motor. So the additional commutation information is necessarily needed to control the mentioned ETC module. In order to estimate and determine the commutation state, it is proposed to properly manipulate the resolution of A/D converter considering the mechanical parameter, that is, the number of motor slot and the ratio of reduction gear. Through this method, the estimation of commutation state for operating the system is possible and the discrete signal for commutation is stably obtained. The validity of the method is examined through the experimental results.
Analysis of the Tolerance Effects of Main Design Parameters on the Vibration Characteristics of a Vehicle Sub-frame
Kim, Bum-Suk ; Kim, Bong-Soo ; Yoo, Hong-Hee ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 100~105
In the design process of an automobile part, several analysis methods are usually utilized to evaluate the performance of the part. However, most automobile design engineers do not directly utilize CAE (Computer Aided Engineering) tools since specific skills are required to obtain practical results. Moreover, CAE requires a huge amount of computation time and cost. In order to resolve these problems, a new design approach named First Order Analysis (FOA) technique has been proposed. In this paper, the FOA technique is employed to design a vehicle sub-frame. An equivalent model of the vehicle sub-frame which only consists of beam elements is proposed and the modal properties obtained with the model are compared to those obtained with a full scale finite element model. The effect of some parameter tolerances on the modal characteristics of the vehicle sub-frame is investigated by employing the FOA equivalent model.
The Simulation of Fuel Economy Considering Transient Control Condition in a Gasoline Engine Vehicle
Jung, Yeon-Sik ; Park, Jin-Il ; Lee, Jong-Hwa ; Park, Kyoung-Seok ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 106~112
Modern vehicles require a high degree of refinement, including good drive ability to meet customer demands. Vehicle drive ability, which becomes a key decisive factor for marketability, is affected by many parameters such as engine control and the dynamic characteristics in drive lines. This paper focuses on the simulation of FTP-75 mode which is considered with spark timing control on transient condition. The acceleration is the most important factor for vehicle fuel economy. The retard of spark timing increases in proportion to acceleration. Likewise, bsfc(break specific fuel consumption) which is affected by spark timing also increases in proportion to acceleration. The result of simulation considered transient condition shows 0.3% of error comparing with a test on chassis-dynamometer.
A Study on the Characteristics of Giant Magneto Resistance using Multi Layers
Kim, Byeong-Woo ; Lee, Young-Seok ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 113~118
We have developed an integrated giant magneto resistance using not only circuit but also integrating technique with semiconductor for automobile application. It has four elements used for giant magneto resistance sensor. Ni-Fe/Cu multi layers were prepared on a glass substrate by magnetron sputtering. The dependence of magneto resistance on the thickness of the Ni-Fe and Cu layers was investigated. The MR ratio showed a saturated a peak at Cu layer
, Ni-Fe layer
, where the MR ratio is about 8.7% at room temperature. By means of Ni-Fe multi film and specific integrating technique, these new giant magneto resistance sensor showed excellent resistance characteristics.
Evaluation of Crashworthiness and NVH Performances of Side Structure with Finite Element Analysis considering Stamping Effects
Kim, Se-Ho ; Kim, Kee-Poong ; Choi, Won-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 119~127
In this paper, the influence of the stamping effect is investigated in the performance analysis of a side structure. The analysis covers the performance evaluation such as the crashworthiness and NVH. Stamping analyses are carried out for the center pillar and the side sill made of high strength steels. Then, numerical simulations are carried out in order to identify the stamping effect on the crashworthiness, the natural frequency and the normal mode. The result shows that the analysis of the side structure considering the forming history leads to a different result from that without considering the forming effect. The variation of the system response fully reveals effects of thinning and hardening of members on the performance prediction of vehicle parts. The analysis results demonstrate that the design of auto-body members should be carried out considering the stamping history for accurate assessment of various performances.
Speed Estimation from Tire Marks for Vehicle Accident Reconstruction
Kim, Min-Seok ; Lee, Ji-Hoon ; Yoo, Wan-Suk ; Kim, Kee-Nam ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 128~133
In this paper, a new technique was suggested to estimate vehicle speed for the traffic accident reconstruction, and accident investigators can estimate initial vehicle speed based on this suggested technique. Turning tests with several vehicle speeds were executed and compared with the motion of the vehicle and the shape of the tire marks. A new method for estimating the coefficient of friction is suggested by using the longitudinal and lateral components of tire marks. And also, a speed calculation graph is suggested to estimate vehicle speed for traffic accident reconstruction.
The Application of Oxygenated Component(Butyl Ether) and EGR in a DI Diesel Engine
Choi, Seung-Hun ; Oh, Young-Taig ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 134~139
This research investigated variations of the engine performance and the exhaust emission characteristic of a direct injection diesel engine by fueling a commercial diesel fuel, which was blended with the di-ether group (butyl-ether: BE). The smoke emission reduced to 26% from the diesel engine with the blending fuel (diesel fuel 80 vol-% + BE 20 vol-%)at the full engine load of 2500 rpm compared to it with the diesel fuel only. The power, torque and brake specific energy consumption of the diesel engine showed very slight differences. The NOx emission from the diesel engine, however, with the blended fuel was higher than with the commercial diesel fuel only. By applying EGR method, as a counter plan of the NOx reduction, this research obtained reductions of the smoke and NOx emission at the same time from the diesel engine with the BE blended diesel fuel.
A Study on the Hysteresis Effects on a Passenger Car Driveline
Kim, Young-Heub ; Park, Dong-Hoon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 140~146
A friction damper is installed in the passenger car driveline in order to dissipate the torsional vibration energy. The frictional damping hysteresis has considerable influences on the driveline vibration characteristics and, therefore, it is one of the most important parameters in the damper design. To investigate the hysteresis effects on the driveline vibration, a dynamic model of the passenger car driveline with manual transmission has developed, and simulations were executed on the several different driving conditions for various hysteresis values. To verify the model, vehicle tests are preformed and the test data were compared with the simulations results. The simulation and test results show good agreements and the model could be used to determine the optimal hyteresis values in early design stage of the damper.
Research on the Injection Condition Calibration Process of a Common-rail DME Fueled Engine
Chung, Jae-Woo ; Kang, Jung-Ho ; Kim, Nam-Ho ; Jeong, Soo-Jin ; Lee, Ho-Gil ; Kang, Woo ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 147~156
As the management of fuel efficiency becomes globally reinforced in attempts to find an environment-friendly vehicle that will operate against global warming, the interest in and the demand for the type of vehicle with a high-efficiency diesel engine using light oil. However, it also emits a greater amount of PM (particulate matter) and NOx than emissions from vehicles using other types of fuels. Therefore, the DME (Dimethyl Ether), an oxygen containing fuel draws attention as an alternative fuel for light oil that can be used for diesel engines since it generates very little smoke. But to develop and compare performance of an electric controlled common-rail DME engine, engine tests requires optimized injection conditions at required engine RPM and engine torque. These injection conditions cannot be set freely and the data configuration through the experimentally repeated application requires much time as well as a significant amount of errors and effort. The object of this study is to configure the basic injection map using the results of the DME engine experiments performed so far. For this, in this study, the functionalization of the required equations were performed along with the basic review of the factors that had influence on the data map. Through this, the information on the injection pressure, injection amount, injection duration, injection timing, etc. under certain operation condition could be obtained.
Research about Thermal Stratification Effect on HCCI Combustion Fueled with Primary Reference Fuel
Lim, Ock-Taeck ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 157~163
The HCCI combustion mode poses its own set of narrow engine operating by knocking. In order to solve this, inhomogeneity method of mixture and temperature is suggested. The purpose of this research is to get fundamental knowledge about the effect of thermal stratification on HCCI combustion of PRF -Air mixture. The temperature stratification is made by buoyancy effect in combustion chamber of RCM. The analysis items are pressure, temperature of in-cylinder gas and combustion duration. In addition, the structure of flames using the two dimensional chemiluminescence's images by a framing camera are analyzed. Under stratification, the LTR starting time and the HTR starting time are advanced than that of homogeneous. Further, the LTR period of homogeneous conditions became shorter than that of the stratified conditions. With the case of homogeneous condition, the luminosity duration becomes shorter than the case of stratified condition. Additionally, under stratified condition, the brightest luminosity intensity is delayed longer than at homogeneous condition.
Automotive Manual Transmission Clutch System Modeling for Foot Effort Hysteresis Characteristics Prediction
Lee, Byoung-Soo ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 164~170
A typical clutch system for automotive manual transmissions transfers hydraulic pressure generated by driver's pedal manipulation to the clutch diaphragm spring. The foot effort history during the period of push is different than the period of the clutch pedal's return. The effort or load difference is called clutch foot effort hysteresis. It is known that the hysteresis is caused by friction. The frictional force and moment are produced between various component contact points such as between the rubber seal and the inner wall inside the hydraulic cylinder and between the diaphragm spring and the pressure plate, etc. Understanding the clutch pedal foot effort hysteresis is essential for a clutch release system design and analysis. The dynamic model for a clutch release system is developed for the foot effort hysteresis prediction and a simulation analysis is performed to propose a tool for analysing a clutch system.
Effect of Nitrogen and Carbon Dioxide on DME Homogeneous Charge Compression Ignition Engine
Jang, Jin-Young ; Bae, Choong-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 171~178
The combustion and exhaust emission characteristics were investigated in an DME fueled HCCI engine. Carbon dioxide, nitrogen and mixed gas, which was composed of carbon dioxide and nitrogen, were used as control parameters of combustion and exhaust emission. As the oxygen concentration in induction air, which was occurred by carbon dioxide, nitrogen and mixed gas, was reduced, the start of auto-ignition was retarded and the burn duration was extended due to obstruction of combustion and reduction of combustion temperature. Due to these fact, indicated mean effective pressure was increased and indicated combustion efficiency was decreased by carbon dioxide, nitrogen and mixed gas. In case of exhaust emission, hydrocarbon and carbon monoxide was increased by reduction of oxygen concentration in induction air. Especially, partial burning was appeared at lower than about 18% of oxygen concentration by supplying carbon dioxide. However it was overcome by intake air heating.
Study of Characterization for Lean NOx Trap Catalysts Utilizing a Bench-Flow Reactor System
Yoon, Cheon-Seog ; Kim, Hak-Yong ; Nguyen, Ke ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 5, 2008, Pages 179~189
The performance of Lean NOx Trap (LNT) based on the catalysts of Pt/K/Ba/
with proprietary washcoat formulation is studied using a bench flow reactor system. To investigate the effect of temperature and gas hourly space velocity (GHSV) on the nitrogen oxides (NOx) trapping capacity as well as NOx breakthrough time and final ratio of
to NO of LNT, series of adsorption isotherms are carried out with simulated exhaust gases of the lean burn engines. Since typical operation of LNT requires periodic regeneration with a short rich excursion, where the stored or trapped NOx is released and subsequently reduced to
, the effect of the duration of lean and rich phase and type of reductants on the NOx conversion is investigated. NOx storage capacity and breakthrough time obtained from adsorption isotherms shows a volcano-type dependence on the temperature with a maximum NOx storage capacity occurring
and with a maximum breakthrough time occurring
at all GHSVs investigated in this study. Also, maximum ratio of
to NO is obtained at
with a GHSV of
Lean/rich cycle of 100 s lean and 5 s rich used with a concentration of 1.33% of
and 4% of CO in the rich phase is found to be optimum at operating temperature of
and a GHSV of