Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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 15, Issue 6 - Nov 2007
Volume 15, Issue 5 - Sep 2007
Volume 15, Issue 4 - Jul 2007
Volume 15, Issue 3 - May 2007
Volume 15, Issue 2 - Mar 2007
Volume 15, Issue 1 - Jan 2007
Selecting the target year
A Study on Feed Rate Characteristics of Motor-driven Cylinder Lubricator with Electronic Control Quill in a Large Two-stroke Diesel Engine
Bae, Myung-Whan ; Jung, Hwa ; Jung, Yeun-Hak ; Kim, In-Deok ; Kang, Chang-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 1~8
Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, authors first developed a motor-driven cylinder lubricator for a Wartsila Switzerland large two-stroke diesel engine. The characteristic of the developed product is that can control automatically the oil feed rate with a load fluctuation by the motor drive and the offset cam. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and to improve performances as a cylinder lubricator. In this study, the effects of pump motor speed, plunger stroke and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the electronically controlled quill injection system and distributer in the developed cylinder lubricator. It is found that the oil feed rates of electronic control and mechanical type quills with the in-cylinder back pressure are differently characterized by the role of accumulator, the viscous resistance of contact area, etc. It can be also shown that the maximum discharge pressure of the electronic control quill is lower than the mechanical type one but the maximum discharge pressure difference of two types decreased as plunger stroke is small, and the maximum delivery pressures of two types increased as plunger stroke, motor speed and back pressure are elevated but the maximum delivery pressure of mechanical type is higher than the one of electronic control type.
The Design and Implementation of a Fault Diagnosis on an Electronic Throttle Control System
Kang, Jong-Jin ; Lee, Woo-Taik ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 9~16
This paper describes the design and implementation of the fault diagnosis on the Electronic Throttle Control(ETC) System. The proposed fault diagnosis consists of an input signal, actuator and a processor diagnosis. The input signal diagnosis can detect the faults of the ETC system's input signals such as the position sensor fault, source voltage fault, load current fault, and desired position fault. The actuator diagnosis is able to detect the actuator fault due to the actuator aging and an obstacle which interfere in the movement of the actuator. The processor diagnosis detects the fault which prevents the microprocessor from operating the ETC software. In order to protect the breakdown of the ETC system and assure the driving safety, appropriate reactions are also proposed according to the detected faults. The safety and reliability of the ETC system can be improved by the proposed fault diagnosis.
The Characteristics of Exhaust Gas Emissions with GTL Fuel
Gwoak, Soon-Chul ; Seo, Chung-Yul ; Kang, Dae-Il ; Park, Jung-Min ; Yim, Yoon-Sung ; Hwan, Chun-Sik ; Eom, Myoung-Do ; Kim, Jong-Choon ; Lee, Young-Jae ; Pyo, Young-Dug ; Jung, Choong-Sub ; Jang, Eun-Jung ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 17~22
GTL(Gas-to-Liquids) fuel technology was converted from the natural gas, coal and biomass into the diesel or kerosene by Fisher-Tropsch synthesis. GTL fuel have very good merits on high cetane number, low density, free sulfur, lower aromatics contents and no poly-aromatic hydrocarbons as well as the autoignition characteristics. These physical properties make it valuable as a diesel fuel with lower emissions than the conventional diesel fuel. Furthermore, GTL fuel can be use not to the engine any modification. Therefore, to evaluate emissions of GTL fuel, the tested diesel vehicles were fueled on blends of GTL fuel/ultra low sulfur diesel fuel(ULSD). And then, we found out that GTL fuel reduced regulated emissions(CO, NOx, HC, PM) compare with conventional diesel fuel.
LPG/CNG Interface Box Hardware Design
An, Jeong-Hoon ; Jung, Jae-Min ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 23~29
In Korea, the number of LPG vehicles is increasing continuously because LPG is cheaper than Gasoline. Also in Europe, the CNG fuel is a good solution to meet
regulation. In order to use LPG/CNG fuel, new EMS ECU must be developed for every type of vehicles and it requires huge development cost. In order to reduce development cost and time, SIEMENS VDO has developed an Interface Box. It supports EMS ECU in the car and manages LPG/CNG fuel injection system. Basically the Interface box can be used with any kind of EMS ECU. The Interface Box controls LPG/CNG injector through the injection command of gasoline EMS ECU. It calculates required amount of based on the fuel temperature and pressure and sends feedback signal to ECU for fuel correction. Also, it controls LPG/CNG specific actuator such a Shut off valves and LPG switch inputs.
Top-Feed Type Port Fuel Injector for Liquefied Petroleum Gas Liquid Phase Injection
Yeom, Ki-Tae ; Park, Jung-Seo ; Bae, Choong-Sik ; Park, Jeong-Nam ; Kim, Sung-Kun ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 30~37
The injection and spray characteristics of top-feed type injector was investigated under liquid phase injection fueled with liquefied petroleum gas (LPG). Different pressures and temperatures of fuel injection system were tested to identify the injection characteristics after hot soaking. MIE-scattering technique was used for verification of successful liquid phase injection after hot soaking. In case of bottom-feed type injector, the injection was accomplished at every experimental condition. In case of top-feed type injector, when the pressure of LPG was over 1.2 MPa, the injection was not executed. However, under the pressure were 1.2 MPa, the liquid phase injection after hot soaking was accomplished. The engine with top-feed type fuel injection equipment was restarted successfully after hot soaking.
Study on Relationship between Discomfort and Body Pressure Distribution on the Seat under Height of Footrest and Angle of Seatpan
Park, Dong-Woon ; Ahn, Se-Jin ; Yoo, Wan-Suk ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 38~43
In this paper, a study is described on finding a relationship between discomfort and body pressure distribution. In the first step, experiments were conducted to find correlation between pressure distribution and discomfort. The experiments of 12 people on 9 seats were performed. In the second step, parameters and correlation coefficients were determined between the measured body pressure distribution and median values of the subjective evaluations of 12 subjects using psychophysical power law.
Experiments on the Influence of the Air Cavity Resonance on the Structural Vibration Modes in Radial Tire
Kim, Yong-Woo ; Jeong, Kyoung-Shin ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 44~49
It is well known that the acoustic cavity inside the tire-wheel assembly contributes to vehicle interior noise. In this paper, we have performed acoustic and structural modal testings to investigate the influences of the acoustic cavity resonance on structural vibration characteristics for the tire in free-suspension and for the loaded tire. The testings have given us some findings, which are reported in this paper.
A Study on Failure Evaluation of Korean Low Floor Bus Structures Made of Hybrid Sandwich Composite
Lee, Jae-Youl ; Shin, Kwang-Bok ; Lee, Sang-Jin ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 50~61
The structural stiffness, strength and stability on the bodyshell and floor structures of the Korean Low Floor Bus composed of laminate, sandwich panels and metal reinforced frame were evaluated. The laminate composite panel and facesheet of sandwich panel were made of WR580/NF4000 glass fabric/epoxy laminate, while aluminum honeycomb or balsa was applied to the core materials of the sandwich panel. A finite element analysis was used to verify the basic design requirements of the bodyshell and the floor structure. The use of aluminum reinforced frame and honeycomb core was beneficial for weight saving and structural performance. The symmetry of the outer and inner facesheet thickness of sandwich panels did not affect the structural integrity. The structural strength of the panels was evaluated using Von-Mises criterion for metal structures and total laminate approach criterion for composite structures. All stress component of the bodyshell and floor structures were safely located below the failure stresses. The total laminate approach is recommended to predict the failure of hybrid sandwich composite structures at the stage of the basic design.
Establishment of Fracture Criteria on Human Femur
Chung, Nam-Yong ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 62~72
Fracture analysis of human bone is necessary to predict the failure of musculoskeletal structures and to heal them by several possible mechanisms under different loading conditions. But human bone is a complex material, with a multiphase, heterogeneous and anisotropic microstructure. Due to the difficulty of obtaining experimental and clinical results, the importance of numerical analysis and computational simulations in biomechanics are increasing gradually. In this study, stress analysis for human femur model is performed by using the 2-dimensional finite element method(FEM) and its stress distribution is determined. From these results, the fracture mechanic parameters are calculated and the fracture criteria on human femur are investigated and discussed.
Optimization of Processing Conditions and Mechanical Properties in Polymer Nanocomposite
Nam, Byeong-Uk ; Hong, Chae-Hwan ; Hwang, Tae-Won ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 73~80
Nanocomposites are used as a new class of polymer system and many researchers have been interested in the clay nanocomposite because of its good mechanical properties, heat resistance, flame retardancy, and barrier property. Modified layered silicates as fillers are dispersed at a nanometer-level within a polymer matrix and then new extraordinary properties are observed. In this study, polypropylene/clay nanocomposites were prepared in a twin screw extruder by the melt compounding method. In order to increase the compatibility of PP with the clay, the MAPP was used as a compatibilizer. And organic modified clays were used as a nanometric filler during the melt extrusion. Through the analysis of SAXS, WAXS, the dispersion of clay was investigated. These nanocomposites compared with a neat polypropylene/talc composite have high modulus, low toughness, and reduced shrinkage at the stable dispersion.
Effect of Antioxidants on the Oxidative Stability of Biodiesel Fuels
Ryu, Kyung-Hyun ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 81~86
Biodiesel fuel that consists of saturated and unsaturated long-chain fatty acid alkyl esters is an alternative diesel fuel produced from vegetable oils or animal fats. However, air causes autoxidation of biodiesel fuel during storage, which can reduce fuel quality by adversely affecting its properties, such as the kinematic viscosity and acid value. One approach for improving the resistance of fatty derivatives to autoxidation is to mix them with antioxidants. This study investigated the effectiveness of five such antioxidants in mixtures with biodiesel fuels produced by three biodiesel manufacturers : tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PrG) and
-tocopherol. Oxidation stability was determined using Rancimat equipment. The results show that TBHQ, BHA, and BHT were the most effective and
-tocopherol was the least effective at increasing the oxidation stability of biodiesel. This study recommends that TBHQ and PrG be used for safeguarding biodiesel fuel from the effects of autoxidation during storage.
Performance Test of the Dual Mode Hybrid Systems
Kim, Nam-Wook ; Yang, Si-U ; Yang, Ho-Rim ; Cho, Sung-Tae ; Park, Yeong-Il ; Cha, Suk-Won ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 87~93
It is complicate to analysis the systems, dual mode hybrid systems, because they are composed of many planetary gear sets. For the performance test, it needs to define the systems with representative parameters. In this paper, system parameters,
, are introduced to define the systems, and an arbitrary system like E-IVT developed by Renault Motors is converted to the general system having equivalent parameters, such as
. Pontryagin principle and Kuhn-Tucker condition method are applied to solve the constrained problems, by which the methodology for accelerating test is generalized, and the results of the simulation are reported. In addition, the effects of alternative strategies are mentioned. The method of fuel economy test at engine mode is also introduced. The results of test at engine mode is different from the results of optimal trajectory, but the fuel economy of the engine mode is related to the highway driving and optimized operating of the system.
An Experimental Study on the Effects of Spark Plug on the Strength of Electromagnetic Waves Radiating at the Spark Ignition System
Choe, Gwang-Je ; Jho, Shi-Gie ; Jang, Sung-Kuk ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 94~101
This paper, we analyzed that the measured data of the radiated power spectrum of electromagnetic waves and the standing wave ratio(SWR) of the spark plug cable and spark plug. The measured data are the power strength of the electromagnetic waves radiated from the spark ignition system, the measured frequency ranges are 110 to 610MHz. The results show that the strength of radiated power spectrum and bandwidth have relation to the SWR of the the spark plug cable and spark plug, and the SWR of them is different because of the characteristics of resistor at the spark plug is different with the manufacturers. From the analyzed results, it can be concluded that the less SWR is little, the less maximum level of power spectrum is weak and bandwidth above the reference level is small.
Development of a Fast-Response
Analyzer using NDIR Technique and Its Application to SI Engine
Lee, Jae-Young ; Min, Kyoung-Doug ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 102~107
A fast response
) analyzer for real-time measurement of carbon dioxide concentration during transient states of internal combustion engines has been developed. This analyzer uses non-dispersive infrared absorption (NDIR) technique for measuring
concentration and Kalman filter for removing noise components from output signals. The analyzer has good linearity, repeatability and drift with a response time of 11 ms; it is sufficiently fast to detect
concentration during transient states of internal combustion engines. The
analyzer was used to measure transient
concentration of exhaust gas of the SI engine with a standard gas analyzer, and the signal of the
analyzer was compared to that of the standard gas analyzer. The two concentrations were well matched during the steady state, and the
analyzer could measure the variations of
concentration during the transient state.
A Study on the Evaluation of Sensation Magnitude of Vertical Vibration of a Steering Wheel
Jang, Han-Kee ; Hong, Seok-In ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 108~113
This study aims to find equivalent comfort contours, reciprocal of frequency weighting curves, for vertical steering wheel vibration. Psychophysical responses were measured from twelve male subjects by using magnitude estimation of relative discomfort due to vertical steering wheel vibrations of magnitude of 0.1 to 1.58
in the frequency range of 4 to 250 Hz. Relative discomfort were estimated with a reference vibration of 0.4
at 31.5 Hz. Equivalent comfort contours were produced from the median of sensation magnitudes judged by twelve subjects, which showed variation in the shapes with increase of vibration magnitude. A shape of the contour came close to the perception threshold curve with decrease of vibration magnitude. When the vibration magnitude increases, the shape changed close to those in the references of Hong and et al (2003). It is also recommended frequency weighting curves for vertical steering wheel vibration must be expressed as a function of vibration magnitude as well as frequency.
The Study of the Development of Inertia Braking System for the Trailer and the Testing Evaluation
Kim, Soon-Yeong ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 114~119
Because the small trailers do not have the main brake system, it is difficult to gain the effective braking performance of the trailers while driving them. Especially it is very hard to brake them on the slope road condition. So we have technically developed Inertia Braking System for the military trailers which have not main braking system. Inertia Braking System is designed to be activated by the inertia force of trailer. It consists of the brake rod, damping cylinder, hand brake lever and brake cables. We have tested the trailer's braking performance. As a result, we have showed that the trailer's braking performance of the trailer equipped with Inertia Braking System, the road driving performance and the braking safety capability are improved dramatically. And we hope that it is rare to happen the accident while driving.
Design of a Robust Controller to Enhance Lateral Stability of a Four Wheel Steer Vehicle with a Nonlinear Observer
Song, Jeong-Hoon ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 120~127
This paper describes the development of a nonlinear observer for four wheel steer (4WS) vehicle. An observer is designed to estimate the vehicle variables difficult to measure directly. A brake yaw motion controller (BYMC), which uses a PID control method, is also proposed for controlling the brake pressure of the rear and inner wheels to enhance lateral stability. It induces the yaw rate to track the reference yaw rate, and it reduces a slip angle on a slippery road. The braking and steering performances of the anti-lock brake system (ABS) and BYMC are evaluated for various driving conditions, including straight, J-turn, and sinusoidal maneuvers. The simulation results show that developed ABS reduces the stopping distance and increases the longitudinal stability. The observer estimates velocity, slip angle, and yaw rate of 4WS vehicle very well. The results also reveal that the BYMC improves vehicle lateral stability and controllability when various steering inputs are applied.
An Experimental Study of Nano PM Emission Characteristics of Commercial Diesel Engine with Urea-SCR System to Meet EURO-IV
Lee, Chun-Hwan ; Cho, Taik-Dong ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 128~136
It is well known that two representative methods satisfy EURO-IV regulation from EURO-III. The first method is to achieve the regulation through the reduction of NOx in an engine by utilizing relatively high EGR rate and the elimination of subsequently increased PM by DPF. However, it results in the deterioration of fuel economy due to relatively high EGR rate. The second is to use the high combustion strategy to reduce PM emission by high oxidation rate and trap the high NOx emissions with DeNOx catalysts such as Urea-SCR. While it has good fuel economy relative to the first method mentioned above, its infrastructure is demanded. In this paper, the number distribution of nano PM has been evaluated by Electrical Low Pressure Impactor(ELPI) and CPC in case of Urea-SCR system in second method. From the results, the particle number was increased slightly in proportion to the amount of urea injection on Fine Particle Region, whether AOC is used or not. Especially, in case of different urea injection pressure, the trends of increasing was distinguished from low and high injection pressure. As low injection pressure, the particle number was increased largely in accordance with the amount of injected urea solution on Fine Particle Region. But Nano Particle Region was not. The other side, in case of high pressure, increasing rate of particle number was larger than low pressure injection on Nano Particle Region. From the results, the reason of particle number increase due to urea injection is supposed that new products are composited from HCNO, sulfate, NH3 on urea decomposition process.
An Experimental Study on Application of UBD20 according to EGR Rate in a CRDI Type Diesel Engine
Shin, Seo-Yong ; Im, Seok-Yeon ; Jung, Young-Chul ; Choi, Doo-Seuk ; Ryu, Jeong-In ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 137~143
An object of this study is to understand the application characteristics in accordance with changes of EGR rate, applying BD20 reformed by ultrasonic energy irradiation to common-rail diesel engine. BD containing about 10% oxygen has attracted attention due to soaring crude oil prices and environmental pollution. This oxygen decreases soot by promoting combustion, but it also increases NOx. To make up for this problem, an EGR system is applied so that NOx might be decreased. In that case, engine power is lowered and exhaust gas is raised. However, the reformed fuel by ultrasonic energy irradiation is changed physically and chemically, promotes combustion, and thus solves such a problem. As the results of the experimemt, we could identify the optimum EGR rate by investigating the engine performance and the characteristics of exhaust materials in accordance with the EGR rate after ultrasonic energy irradiation to BD20 and applying it to common-rail diesel engine. The optimum EGR rate that can satisfy both engine performance and characteristics of exhaust materials was in the range of 15%.
Analysis of Diesel Nano-particle Number Distribution Characteristics for Three Different Particle Measurement Systems
Lee, Jin-Wook ; Kim, Hong-Suk ; Cho, Gyu-Baek ; Jeong, Young-Il ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 144~150
In recent years, the particle number emissions rather than particulate mass emissions in automotive engine have become the subject of controversial discussions. Recent results from the health effects studies imply that it is possible that particulate mass does not properly correlated with the variety of health effects attributed to diesel exhaust. So, the concern is instead now focusing on nano-sized particles emitted from I. C. engine. This study has been performed for the better understanding about the engine nano-particle for 3-measurement systems with different measuring principle. Firstly, EEPS is a newly introduced instrument for size distribution measurement of engine exhaust particles. It can measure nano-particles with an adequate resolution and in real time. In this study, the characteristics of EEPS were compared with ELPI and SMPS. As a research results, EEPS showed a same effect of engine load on the size distribution with ELPI and SMPS. But the quantitative results of EEPS were more similar to SMPS than ELPI, because the EEPS and SMPS use a same principle for classifying particles by size. The capability for transient measurement of EEPS was equivalent to that of ELPI.
The Effect of Control of the VGT and EGR in a Turbocharged Common-Rail Diesel Engine on Emissions under Partial Loads Conditions
Jeong, Soo-Jin ; Chung, Jae-Woo ; Kang, Jeong-Ho ; Kang, Woo ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 151~158
The static and dynamic behaviour of VGT and EGR systems has a significant impact on overall engine performance, fuel economy and exhaust emissions. This is because they define the state and composition of the air charge entering the engine. This work focused on the effect of the aperture ratio of VGT and EGR on the emission and flow characteristics under partial loads conditions. The investigation carried out using 2 liter PCCI 4 cylinder diesel engine with VGT and EGR. The result of this study shows that smoke increases with increasing EGR rate and NOx decreases with increasing EGR rate. It was also found that the residual gas contents greatly impact on soot emission under partial load condition. Finally, it can be concluded that VGT and EGR aperture ratio can greatly impact not only on soot and NOx but also air charging.
A Study on the Effects of EGR with Syngas Addition in a Gasoline Engine
Yun, Young-Jun ; Choi, Young ; Kang, Kern-Yong ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 159~164
The purpose of this study is to reduce harmful emission gases in the range of stable combustion without loss of a thermal efficiency. Therefore, effects of both exhaust gas recirculation(EGR) and synthetic gas addition on engine performance and emission were investigated in a gasoline engine. Synthetic gas(syngas), which is in general prepared from reforming gasoline, was utilized in order to promote stable combustion. The major components of syngas are H2, CO and
gases. The percentage of syngas addition was changed from 0 to 30% in energy fraction and EGR rate was varied up to 30%. As a result,
as a parameter of combustion stability was decreased and THC/
emissions were reduced with the increase of syngas addition. And
was increased with the increase of EGR but
emission was greatly reduced. In addition, under the region where the EGR rate is around 20%, thermal efficiency was improved.
Effect and Reduction Method of Rotating Unbalance Mass on Vibration Characteristics of Front Axle
Park, Tae-Wone ; Kim, Kee-Joo ; Choi, Byung-Ik ; Sung, Chang-Won ; Kim, Sang-Shik ; Kim, Heon-Young ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 165~169
The purpose of this study is to investigate the effect of rotating unbalance mass on vibration characteristics of the front axle. The power-train systemof the vehicle is composed of several rotating parts. These component parts should be properly balanced by the balancing machine, however,sometimes these have the unbalance mass which causes the critical vibration in the vehicle. Therefore, this study suggests the vibration improvement method based on reducing the unbalance mass through changing the assembly type between the companion flange and the constant velocity joints. In addition, the way to increase the inertia moment of the companion flange was proposed.
A Study on the Fluid H in Automotive Air Conditioning System as an Alternative Refrigerant
Choi, Jeong-Won ; Nam, Soo-Byeong ; Bang, Scott ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 170~176
It is time to prepare the phaseout of R134a, the current refrigerant, in automotive air conditioning system because the EC deadline has been coming with new platform vehicles in 2011 and all vehicles by 2017. Until now a high-pressure carbon dioxide(
) system is the leading replacement of R134a in European auto-makers but there is no firm agreement in the world automotive market. Recently three new fluids have been announced as the possibilities from Honeywell, DuPont and INEOS Fluor. The new alternative refrigerant should meet the requirements like non flammable, non toxic, no ozone depletion effect and low GWP(under 150 to meet EC regulation). The objectives of this paper are to review the fluid H from Honeywell, the more possible alternative refrigerant in 3 new fluids, compare the properties of R134a & fluid H and see the possibility as a replacement of R134a. In this experimental paper we ran and reviewed the cooling performance data in the bench system, the vehicle and the field test. We found the possibility of fluid H system to meet the R134a system performance with some hardware modifications but agreed that it is still needed to study about the long term safety, environmental effects, material compatibilities and so on.
Frequency Response Characteristics of Automotive Hydraulic Pipelines
Kim, Do-Tae ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 6, 2007, Pages 177~182
In this paper, automotive hydraulic pipeline systems are modeled in which a straight blocked pipe, two pipes with sudden expansion or contraction are connected in series and terminated with a chamber. The frequency response characteristics of these composite pipeline systems are investigated experimentally. The theoretical analysis for various pipe configurations is base on transfer matrix method with frequency dependent viscous friction distributed parameter pipeline model. The gain and phase of transfer functions are included for comparison with experimental results. There is close agreement between the results of experimental and theoretical determination of pressure response in automotive hydraulic pipeline systems.