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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
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Journal DOI :
The Korean Society of Automotive Engineers
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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
Study of EMI Suppression Method Applied on DC Motor Driver of Power Tail Gate
Kim, Yeong-Sik ; Yoon, Yong-Soo ; Jung, Hun ; Gohng, Jun-Ho ; Lee, Sang-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 1~7
This paper presents electromagnetic interference(EMI) suppression method applied on the direct current(DC) motor driver for power tail gate control. EMI noise is generated by the fast switching of power devices connected to electric loads. It has become a matter of concern because of the vast increase in the number and sophistication of electronic system in automotive environment. The proposed EMI reduction method is based on the principle of reducing the transient speed of power devices by changing the parameters of the driver circuit related to the power MOSFET. In this paper, power losses were calculated by loss equations and thermal simulation was used to evaluate the effect on printed circuit board. Based on these results, the DC motor driver was fabricated and tested. The proposed method can help to design a DC motor driver which allows it to obtain an acceptable compromise between power losses and EMI.
A Study on the VOCs Emission Characteristics by the Light Duty Diesel and LPG Fueled Vehicles
Eom, Myung-Do ; Ryu, Jung-Ho ; Han, Jong-Su ; Lyu, Young-Sook ; Kim, Dae-Wook ; Kim, Jong-Choon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 8~13
Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.
An Experimental Study on Flammability Limits and Combustion Characteristics of Synthetic Gas in a Constant Combustion Chamber
Cho, Yong-Seok ; Lee, Seang-Wock ; Won, Sang-Yeon ; Park, Young-Joon ; Kim, Duk-Sang ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 14~21
Synthetic gas is defined as reformed gas from hydrocarbon-based fuel and the major chemical species of the synthetic gas are
, CO and
. Among them, hydrogen from synthetic gas is very useful species in chemical process such as combustion. It is a main reason that many studies have been performed to develop an effective reforming device. Furthermore, other technologies have been studied for synthetic gas application, such as the ESGI(Exhaust Synthetic Gas Injection) technology. ESGI injects and burns synthetic gas in the exhaust pipe so that heat from hydrogen combustion helps fast warmup of the close-coupled catalyst and reduction of harmful emissions. However, it is very hard to understand combustion characteristic of hydrogen under low oxygen environment and complicated variation in chemical species in exhaust gas. This study focuses on the characteristics of hydrogen combustion under ESGI operating conditions using a CVC(Constant Volume Chamber). Measurements of pressure variation and flame speed have been performed for various oxygen and hydrogen concentrations. Results have been analyzed to understand ignition and combustion characteristics of hydrogen under lower oxygen conditions. The CVC experiments showed that under lower oxygen concentration, amount of active chemicals in the combustion chamber was a crucial factor to influence hydrogen combustion as well as hydrogen/oxygen ratio. It is also found that increase in volume fraction of oxygen is effective for the fast and stable burning of hydrogen by virtue of increase in flame speed.
Size and Shape Optimization of the Oil Pump for Fuel Consuming Reduction
Jo, Sok-Hyun ; Nam, Kyung-Woo ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 22~28
Generally block imbedded type oil pump is adopted to make a small engine. In this paper 1D/3D numerical simulations were conducted to reduce energy consumption of the block imbedded type oil pump. At each stage of engine development we have estimated the oil flow rate and pressure to optimize oil pump sizes by using the 1D system analysis and then accomplished 3D CFD(Computational Fluid Dynamics) simulations to optimize oil pump shapes including inlet/outlet port. As a result, the energy consumption of oil pump has been reduced to nearly 27% and the engine fuel consumption to
A Study on Orbital Forming Analysis of Automotive Hub Bearing using the Explicit Finite Element Method
Cho, Hyun-Jik ; Koo, Jeong-Seo ; Bae, Won-Rak ; Lim, Jong-Soon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 29~36
In this paper, the orbital forming analysis of an automotive hub bearing was studied to predict forming performances using the explicit finite element method. To find an efficient solution technique for the orbital forming, axisymmetric finite element models and 3D solid element models were solved and numerically compared. The time scaling and mass scaling techniques were introduced to reduce the excessive computational time caused by small element size in case of the explicit finite element method. It was found from the numerical simulations on the orbital forming that the axisymmetric element models showed the similar results to the 3D solid element models in forming loads whereas the deformations at the inner race of bearing were quite different. Finally the strains at the inner race of bearing and the forming forces to the peen were measured for the same product of the numerical model by test, and were compared with the 3D solid element results. It was founded that the test results were in good agreements with the numerical ones.
Performance Evaluation of a
Heat Pump System for Fuel Cell Vehicles
Kim, Sung-Chul ; Park, Jong-Chul ; Kim, Min-Soo ; Won, Jong-Phil ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 37~44
The global warming potential (GWP) of
refrigerant is 1/1300 times lower than that of R134a. Furthermore, the size and weight of the automotive heat pump system can decrease because
operates at high pressure with significantly higher discharge temperature and larger temperature change. The presented
heat pump system was designed for both cooling and heating in fuel cell vehicles. In this study, the performance characteristics of the heat pump system were analyzed for heating, and results for performance were provided for operating conditions when using recovered heat from the stack coolant. The performance of the heat pump system with heater core was compared with that of the conventional heating system with heater core and that of the heat pump system without heater core, and thus the heat pump system with heater core showed the best performance among the selected heating systems. On the other hand, the heating performance of two different types of coolant/air heat pump systems with heater core was compared each other at various coolant inlet temperatures. Furthermore, to use exhausted thermal energy through the radiator, experiments were carried out by changing the arrangement of a radiator and an outdoor evaporator, and quantified the heating effectiveness.
Analysis on the Power Spectrum of Electromagnetic Waves Radiating from the Distributorless Spark Ignition System
Choe, Gwang-Je ; Jho, Shi-Gie ; Jeung, Weol-Rark ; Jang, Sung-Kuk ; Kang, Shin-Han ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 45~51
This paper presents theoretical and experimental analysis on the characteristics of the power spectrum of electormagnetic waves radiating from the spark plug and their cables of a distributorless ignition system. The theoretical study was conducted applying the microwave transmission line theory and the antenna theory. The experimental works were carried out to measure the standing wave ratio(SWR) and the radiation power spectrum of this system. As a result, it has been found that a spark plug and its cable is working as a monopole antenna radiating elelctromagnetic waves. Because of its similar structure to a monopole antenna, the envelope of radiation power spectrum distribution has a bell shape which can be obtained from a monopole antenna operating as a series resonant circuit. The frequency characteristics from the SWR measurements show a similar frequency characteristics of power spectrum of the system studied. Also, it has been found that the density of the power spectrum of the system fitting a long time used spark plug is higher than that of fitting a new spark plug.
A Study on the Side Collision Accident Reconstruction Using 3-Dimensional Crash Analysis
Jang, In-Sik ; Kim, Il-Dong ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 52~63
The side collision reconstruction algorithm is developed using three dimensional car crash analysis. Medium size passenger car is modeled for finite element analysis. Total 24 side collision configurations, four different speed and six different angle, are set up for making side collision database. Deformation index and degree index are built up for each collision case. Deformation index is a kind of deformation estimate averaging displacement of side door of crashed car from finite element analysis result. Angle index is constructed measuring deformed angle of crashing car. There are two kinds of angle index, one is measured at driver's side and the other is measured at passenger's side. Also a collision analysis information in side of cars is used for giving a basis for scientific and practical reason in a reconstruction of the car accident. The analysis program, LS-DYNA3D is utilized for finite element analysis program for a collision analysis. Those database are used for side collision reconstruction. Side collision reconstruction algorithm is developed, and applied to find the collision conditions before the accident occurs. Three example collision cases are tried to check the effectiveness of the algorithm. Deformation index and angle index is extracted for the case from the analysis result. Deformation index is compared to the established database, and estimated collision speed and angle are introduced by interpolation function. Angle index is used to select a specific collision condition from the several available conditions. The collision condition found by reconstruction algorithm shows good match with original condition within 10% error for speed and angle. As a result, the calculation from the reconstruction of the situation is reproducing the situation well. The performance in this study can be used in many ways for practical field using deformation index and degree index. Other different collision situations may be set up for extending the scope of this study in the future.
Application of CFD-FEM Coupling Methodology to Thermal Analysis on the Large-size Marine Diesel Engine
Kim, Han-Sang ; Min, Kyoung-Doug ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 64~70
Temperatures of engine head and liner depend on many factors such as spray and combustion process, coolant passage flow and engine related structures. To estimate the temperature distribution of engine structure, multi-dimensional computational fluid dynamics (CFD) codes have been mainly adopted. In this case, it is of great importance to obtain the realistic wall temperature distribution of entire engine structure. In the present work, a CFD-FEM coupling methodology was presented to address this demand. This approach was applied to a real large-size marine diesel engine. CFD combustion and coolant flow simulations were coupled to FEM temperature analysis. Wall heat flux and wall temperature data were interfaced between combustion simulation and solid component temperature analysis via translator by a commercial CFD package named FIRE by AVL. Heat transfer coefficient and surface temperature data were exchanged and mapped between coolant flow simulation and FEM temperature analysis. Results indicate that there exists the optimum cell thickness near combustion chamber wall to reasonably predict the wall heat flux during combustion period. The present study also shows that the effect of cell refining on predicting in-cylinder pressure during combustion is negligible. Hence, the basic guidance on obtaining the wall heat flux needed for the reasonable CFD-FEM coupling analysis has been established. It is expected that this coupling methodology is a robust tool for practical engine design and can be applied to further assessment of the temperature distribution of other engine components.
Electronic Throttle Body Model Allowing for Non-linearity of DC Motor Driver
Jin, Sung-Tae ; Kang, Jong-Jin ; Lee, Woo-Taik ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 71~77
This paper proposes an Electronic Throttle Body (ETB) model considering a non-linearity of DC motor driver which is integrated with a H-bridge and a gate driver. A propagation delay and reverse recovery time of switching components cause non-linear characteristic of DC motor driver. This non-linearity affects not only the amateur voltage of DC motor, but also entire behaviour and parameters of ETB. In order to analyze the behavior of ETB more accurately, this non-linear effect of DC motor driver is modeled. The developed ETB model is validated by use of the step response and ramp response experiments, and it shows relatively accurate results compared with linear DC motor driver model.
Fuel Stratification Effects of LPG-DME Compression Ignition Engine
Yeom, Ki-Tae ; Bae, Choong-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 78~85
The exhaust emission characteristics of a liquefied petroleum gas-di-methyl ether (LPG-DME) compression ignition engine was investigated under homogeneous charge, stratified charge and diffusion combustion conditions. LPG was used as the main fuel and injected into the combustion chamber directly. DME was used as an ignition promoter and injected into the intake port. Different LPG injection timings were tested to verify the combustion characteristics of the LPG-DME compression ignition engine. The combustion was divided into three region which are homogeneous charge, stratified charge, and diffusion combustion region according to the injection timing of LPG. The HC emission was reduced with LPG stratification. However, the carbon monoxide and particulate matter emissions were increased. The ignition timing was advanced with LPG stratification. This advance combustion was because of charge temperature and cetane number stratification with LPG.
Hydro-forming Process of Automotive Engine Cradle by Computer Aided Engineering (CAE)
Kim, Kee-Joo ; Choi, Byung-Ik ; Sung, Chang-Won ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 86~92
Recently, the use of tubes in the manufacturing of the automobile parts has increased and therefore many automotive manufactures have tried to use hydro-forming technology. The hydro-forming technology may cause many advantages to automotive applications in terms of better structural integrity of the parts, lower cost from fewer part count, material saving, weight reduction, lower spring-back, improved strength and durability and design flexibility. In this study, the whole process of front engine cradle (or front sub-frame) parts development by tube hydro-forming using steel material having tensile strength of 440MPa grade is presented. At the part design stage, it requires feasibility study and process design aided by CAE (Computer Aided Design) to confirm hydro-formability in details. Effects of parameters such as internal pressure, axial feeding and geometry shape on automotive sub-frame by hydro-forming process were carefully investigated. Overall possibility of hydro-formable sub-frame parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of tube material on every forming step such as pre-bending, preforming and hydro-forming. At the die design stage, all the components of prototyping tools are designed and interference with press is examined from the point of geometry and thinning.
An Experimental Study on dte Performance of Plasma-DeNOx Catalyst widt Supplying Hydrocarbon Reductant
Hur, Dong-Han ; Min, Kyoung-Doug ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 93~99
To improve the performance of plasma-DeNOx catalyst, a research on active system was performed experimentally. Two hydrocarbons, propane and diesel, were used as a reductant in this study. First, using propane, basic performances of plasma-DeNOx catalyst such as the effects of plasma and C/N ratio were measured at the various engine operating conditions. NOx conversion of catalyst was improved as plasma power or C/N ratio was increased. Next, diesel was injected in the exhaust gas flow as a reductant. The first test using diesel as a reductant is spray visualization in a high temperature flow and spray images were utilized for analysis of posterior test results. To evaluate the effect of an injection direction, it was compared with 6 installation methods of diesel injector due to THC concentrations at the inlet of plasma. From the results, injector was installed toward downstream direction below the pipe. Then, basic performances of plasma-DeNOx catalyst with various injection quantities were measured. As an injection quantity was increased,
conversion of plasma reactor was increased but NOx conversion of catalyst was nearly zero. This was because NOx conversion of catalyst had slowed as time goes by due to black particles which had been adhered to the catalyst.
A Study on the Cross-drilling Effects of Brake Disc Rotor
Seo, Young-Jin ; Oh, Je-Ha ; Lee, Jun-Sang ; Kang, Kyoung-Soo ; Jung, Geun-Sung ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 100~105
Cross-drilling on the brake disc is generally known as a way of improving cooling efficiency. In other theories, cross-drilled holes act like a path of gas or water and are also known that they can reduce fading and wetting of brake rotors. However, in disc rotors with cross-drilling, thermal crack phenomena have been reported more frequently and more manufacturing cost should be paid than non cross-drilled disc rotors. In this study, to examine various effects of cross-drilling on the brake disc, two kinds of brake disc rotors, cross-drilled and non cross-drilled, were used in computational fluid dynamic analyses and dynamometer tests.
Noise Source Identification of a Starter Motor using DOE (Design of Experiments: A Case Study)
Park, Soon-Sik ; Lim, Byoung-Duk ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 106~113
The starter motor noise is usually well identified by the customers since it is operated while the engine is quiet, and leaves distinct impressions of the vehicle. In this study the design of experiments(DOE) was applied to the identification of the noise sources of direct drive starter motor since this process usually requires lengthy analysis and elaborate experiments. In the first stage of the test, five controllable factors(alignment and dynamic unbalance of armature, tightening torques of T/bolt and center bracket bolt, and alignment of the center bracket-yoke-rear bracket), excluding static unbalance, are sorted out of all possible factors. Test results showed that the dynamic unbalance and misalignment of armature are the major factors. However, the error level of the first test was relatively high, indicating that there might be some missing major factors. In the second stage test the results showed that both static and dynamic unbalances are the dominant factors contributing to more than 80% of the overall noise, while the misalignment contributes around 12%. Error of the second test was about 4% that could be considered satisfactory. The noise level of the optimal product was predicted to be reduced by 19dBA, and verification test showed the average noise reduction of 16.8dBA with the standard deviation of 3.2dBA, and proved the usefulness of the whole DOE process.
Analysis of Diesel Nano-particle Characteristics for Different Vehicle Test Mode in Diesel Passenger Vehicle
Lee, Jin-Wook ; Jung, Min-Won ; Jeong, Young-Il ; Cha, Kyong-Ok ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 114~120
Recently, the nano-PM's number concentration emitted by diesel internal combustion engine has focused on attention because this particulate matters are suspected being hazardous of human health. In this study, The nano-PM mass and size of diesel passenger vehicles were measured on chassis dynamometer test bench. The particulate matters(PM) emissions of these vehicles were investigated by number concentration too. A condensation particle counter(CPC) system was applied to measure the particle number and size concentration of diesel exhaust particles at the end of dilution tunnel along the NEDC(ECE15+EUDC) and CVS-75 vehicle test mode. As the research result, the characteristic of vehicle test mode on the diesel nano-particle number and size distribution was investigated in this study.
Cooling Heat Transfer Characteristics of Carbon Dioxide in a Horizontal and Helically Coiled Tube
Son, Chang-Hyo ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 121~126
The cooling heat transfer coefficient of
(R-744) in a horizontal and helically coiled tube was investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater, evaporator and gas cooler (test section). The test section consists of a horizontal stainless steel tube and hellically coiled copper tube of 4.57 and 7.75 mm. The experiments were conducted at saturation temperature of 100 to
, and mass flux of 200 to
. The test results showed the variation of the heat transfer coefficient tended to decrease as cooling pressure of
increased. The heat transfer coefficient with respect to mass flux increased as mass flux increased. The experimental results were also compared with the existing correlations for the supercritical heat transfer coefficient, which generally underpredicted the measured data. However, the experimental data showed a relatively good agreement with the correlations of Pitla et al. except for the pseudo critical temperature.
A Study on the Characteristics of the Electronic EGR Valve for Gasoline Engine
Park, Cheol-Woong ; Kim, Chang-Gi ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 127~133
Since the 1960's, exhaust gas recirculation(EGR) has been used effectively in spark ignition(SI) engines to control the exhaust emissions of the oxides of nitrogen(NOx). The most important requirements for the application of EGR systems to conventional SI engines are controllable flow rate and good dynamic response. In order to evaluate the characteristics of the electronic EGR valve, a test bench which is consisted of blower, heater, air flow meter and driving unit for electronic EGR valve was set up to simulate engine operating conditions. During the tests, the valve actuation parameters were controlled and the valve lifts and flow rates were measured to infer the characteristics of EGR valve. The results confirmed the capabilities of mathematical analysis and it seems that the correction for the valve lift and potentiometer output is necessary to achieve precise control of EGR rates.
Feasibility Study on Robust Calibration by DoE to Minimize the Exhaust Emission Deviations from Injector Flow Rate Scatters
Chang, Jin-Seok ; Cheong, Jae-Hoon ; Jo, Chung-Hoon ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 134~143
The hardware scatters as well as the engine parameters calibration have strong influences on exhaust emissions in recent diesel engines. In this research DoE(Design of Experiments) optimizations were done to study the possibility of minimizing the emission deviations caused by flow rate scatters of the injectors. It has been shown that the optimization of engine calibration, which minimizes the emission deviations, is feasible by establishing a target function representing the emission deviations for test results of maximum, mean and minimum flow rate injectors. It has also been shown that optimization of both emission deviations and emission level is possible by sequential DoE optimizations of the target functions representing the emission level and the emission deviations respectively with the appropriate boundary limits.
Development of the All-Wheel-Steering Algorithm using Dynamic Analysis of the Bi-modal Vehicle
Jeon, Yong-Ho ; Park, Tae-Won ; Lee, Soo-Ho ; Kim, Duk-Gie ; Moon, Kyung-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 144~151
The bi-modal vehicle is composed of two car-bodies and three axles. Each axle of the vehicle has an independent suspension and all wheels are steerable. Since the bi-modal vehicle has longer wheelbase than most urban buses, the All-Wheel-Steering(AWS) system is adapted for to ensure safe driving and proper turning radius on a curved road. This paper proposes an AWS control algorithm for stable driving of bi-modal vehicle. Steering angles and directions of each axle of bi-modal vehicle changed according to the driving environment and steering modes. In the case that front and rear axles should be steered in opposite directions is a negative mode, and the other case that the axles should be steered in the same direction is a positive mode. For example, in the positive mode, front and real axles are steered in the same direction, while in the negative mode, they are steered in the opposite direction. A multibody model of the vehicle is used to verify the performance of the steering algorithm and simulation results of 2WS are compared with those of AWS under the same condition.
A Study on Sprny and Combustion Characteristics by Temperature of Biodiesel Fuel
Baik, Doo-Sung ; Lee, Seang-Wock ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 152~157
The biodiesel becomes one of the favorite alternative fuel applied to diesel engines. This research aims to understand the physics of spray and combustion characteristics of a biodiesel fuel in a constant volume chamber. For spray visualization, biodiesel was injected into a combustion chamber and a high speed camera was applied at various combustion conditions. To investigate heat-release rates and flame propagations, spark was ignited on a hydrogen fuel for the premixed combustion and then biodiesel was injected directly. In addition, parametric study was made by various geometries of combustion chambers and temperatures of fuels and injection pressures. This technology may contribute to improve the performance of bio-diesel engine and reduce emissions in future.
Analysis Model Development for Designing of Hydraulic Power Steering System
Jang, Joo-Sup ; Yoon, Young-Hwan ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 158~165
Hydraulic power steering system has been adopted in seniority passenger and commercial vehicle system for an easy maneuverability and a smoother ride. In this study, hydraulic power steering system analysis model which includes hydraulics and mechanical sub-systems was developed using commercial software, AMESim in order to predict characteristics for various steering components. Each component which constructs system was modeled and verified by experimentally obtained characteristics curves of each components. The agreement between simulation and experimental results shows the validity of the simulation model. The parameter sensitivity analysis such as valve opening area, torsional stiffness for system design are carried out by the analysis and experimental method.
A Study on the Development of the Automatic Performance-Test-Bench for Drag Torque
Lee, Seong-Ho ; Mok, Hak-Soo ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 166~174
Recently, the automotive industry has been developing rapidly. With the progress parts of the automobile components need high quality and the reliability. Among them, braking unit is essential device, and acquire the reliability through the performance test of brake. This study was aimed to design the performance-test-bench to measure the drag torque which has effect on caliper in braking unit. In this progressive technology, it is vital importance to use hydraulic and pneumatic, and to combine test bench with instrumentation engineering technology. This system to construct the design of hydraulic and pneumatic circuit, interface technique between sensors and personal computer, data acquisition and display design, and integrated control are very important technology. Moreover, reliable data are obtained through vacuum system and hydraulic and pneumatic system by using of booster and brake master cylinder which are actually applied to automobile. Then, data signal detector sensors for speed, pressure and torque is attached on this system. Therefore, in this study, we designed a performance-test-bench by and we also made an total control system using personal computer which is more progressive and flexible method than existing PLC control.
Structural Design Optimization of the Aluminum Space Frame Vehicle
Kang, Hyuk ; Kyoung, Woo-Min ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 175~180
Due to the global environment problems and the consumer's need for higher vehicle performance, it becomes very important for the global car makers to reduce vehicle weight. To reduce vehicle weight, many car makers have tried to use lightweight materials, for example, aluminum, magnesium, and plastics, for the vehicle structures and components. Especially, the ASF(aluminum space frame) is known for the excellent concept of the vehicle to satisfy structural rigidity, safety performance and weight reduction. In this research, the design of experiments and the multi-disciplinary optimization technique were utilized to meet the weight and structural rigidity target of the ASF. For the structural performance of the ASF, the locations and the size of aluminum extruded frames, aluminum cast nodes, and the aluminum sheets were optimized. As a result, the optimization design procedure has been set up to meet both structural and weight target of the ASF, and the assembled ASF showed good structural performance and weight reduction.
An Experimental Study on the Emission Characteristics of GTL Fuel with Injection Timings in CRDi Single Cylinder Engine
Kim, Byoung-Jun ; Lee, Yong-Gyu ; Choi, Kyo-Nam ; Jeong, Dong-Soo ; Cha, Kyung-Ok ;
Transactions of the Korean Society of Automotive Engineers, volume 16, issue 1, 2008, Pages 181~187
Recently, alternative fuels are drawing more attentions due to the increasing need for lower emission characteristics and fuel consumption rate in automotive engines. The GTL(gas to luquid) is the one of most favored candidates. It has higher cetane number(more than 75) and almost negligible sulphur and aromatic contents. Therefore, enhanced emission characteristics are expected even in the application in diesel engines without any modification. In this study, the cylinder pressure and heat release, emission characteristics with fuel injection timings are compared between diesel and GTL fuel in the single cylinder diesel engine. Noticeable reduction in PM, THC and CO emission are observed due to lower sulphur and aromatic contents in GTL. Also, the ignition delay decreased due to higher cetane number of GTL, which slightly decreased the amount of NOx emissions. With the retards of main injection timing, NOx decreases more for the case of GTL, while the level of THC and CO emissions still remains lower than the case of diesel. Therefore, there is much room for the control of injection timing for NOx reduction without sacrificing THC and CO emissions. With the retards of main injection timing, Small size distribution of PM became lager and there amount increased. But from all conditions, size distribution of PM for the case GTL was lower than Diesel.