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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 4, Issue 6 - Dec 1996
Volume 4, Issue 5 - Sep 1996
Volume 4, Issue 4 - Aug 1996
Volume 4, Issue 3 - May 1996
Volume 4, Issue 2 - Mar 1996
Volume 4, Issue 1 - Jan 1996
Selecting the target year
Airbag Accelerometers Using Silicon Epitaxial Layers
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 9~15
A silicon microaccelerometer is designed and fabricated using silicon epitaxial layers for automotive electronic airbag applications. A cantilever structure is chosen for high sensitivity and piezoresistive detection method is adopted for circuit simplicity and low cost. An optimum design is used to find optimum microstructure sizes for maximum sensitivity subject to performance requirements and design constraints on natural frequency, damping ratio, maximum allowable stress and microfabrication limitations. The microaccelerometer is fabricated by micromachining processing steps, composed of material-selective and orientation-dependent chemical etching techniques. Fabricated prototype shows a sensitivity of 88.6
/g within a resonant frequency of 1.75KHz. Estimated performance of the microaccelerometer is compared with measured one. Discrepancy between the theoretical values and the experimental values is discussed together with possible sources of the errors.
A Dynamic Explicit/Rigid-plastic Finite Element Analysis and its Application to Auto-body Panel Stamping Process
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 16~25
In the present work a rigid-plastic finite element formulation using dynamic explicit time integration scheme is proposed for numerical analysis of auto-body panel stamping processes. The rigid-plastic finite element method based on membrane elements has long been employed as a useful numerical technique for the analysis of sheet metal forming because of its time effectiveness. A damping scheme is proposed in order to achieve a stable solution procedure in dynamic sheet forming problems. In order to improve the drawbacks of the conventional membrane elements, BEAM(abbreviated from Bending Energy Augmented Membrane) elements are employed. Rotational damping and spring about the drilling direction are introduced to prevent a zero energy mode. The lumping scheme is employed for the diagonal mass matrix and linearizing dynamic formulation. A contact scheme is developed by combining the skew boundary condition and the direct trial-and-error method. Computations are carried out for analysis of complicated auto-body panel stamping processes such as forming of an oilpan, a fuel tank and a front fender. The numerical results of explicit analysis are compared with the implicit results with good agreements and it is shown that the explicit scheme requires much shorter computational time, especially when the problem becomes more complicated. It is thus shown that the proposed dynamic explicit rigid-plastic finite element method enables an effective computation for complicated autobody panel stamping processes.
Turbulent Flow and Heat Transfer in an Annular Passage with Repeated-Ribbed Roughness on Both Walls
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 26~36
The fully developed turbulent momentum and heat transfer induced by the square-ribbed roughness elements on both the inner and outer wall surfaces in concentric annuli are studied analytically based on a modified turbulence model. The analytical results of the fuid flow are verified by experiment. The experiment is done with a pitot tube and a X-type hot wire anemometer to measure the time mean velocity profiles, zero shear stress positions, maximum velocity positions and friction factors, and etc. shown in Fig.1. The resulting momentum and heat transfer are discussed in terms of various parameters, such as the radius ratio, the relative roughness, the roughness density, Reynolds number, Nusselt bumber and Prand시 number. The study demonstrates that certain artificial roughness elements may be used to enhance heat transfer rates with advantage from the overall efficiency point of view by investigating turbulent flows and heat transfer in Fig.1.
Misfire Detection by Using the Crankshaft Speed Fluctuation(2) : Vehicle Test
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 90~99
To keep up with the regulation of OBD II(on board diagnostics II), many detection methods for engine misfire have been developed. Among them, the method of using the crankshaft speed fluctuation is the most noticeable in the point of view of lower cost and easier installation than any others. On the basis of the results obtained from the previous engine-dynamometer test, the integrating torque index (ITI) has been introduced. In this research, the instrumental and the interfacing systems to engine control unit(ECU) are developed for the vehicle test. Therefore, the vehicle and chassis-dynamometer test can be carried out in addition to the rough road test. From this test, the previousproposed method proved that it can be applied to the real vehicle.
An Analysis of Vehicle Handling Characteristics with ADAMS
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 109~118
An analysis of handling characteristics of a vehicle is performed for step and pulse steering input, which may be very useful in suspension design stage. Many developed computer programs for vehicle dynamics require test data of compliance effects for proto type car. Therefore, these programs are not suitable for automobile development stage. Using the raw design data of suspension and steering system, we analyze the vehicle behavior for step and pulse steering input with commercial multibody dynamics program, ADAMS. Simulated results are in good agreement with vehicle test results. Vehicle handling characteristics parameters which are very useful in automobile suspension design are evaluated from the analysis.
Prediction of Turbulent Flows with Separation and Swirl Using the RNG K-
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 119~129
This study is concerned with the critical evaluation of predicative capability of a k-
turbulence model using the Renormalization Group(RNG) theory. The present numerical model for solution of the Navier-Stokes System is based on the modified PISO algorithms. Computations have been performed with the RNG-based K-
model for the two-dimensional flow over a backward-facing step, a confined coaxial jet, and a swirling flow in a swirl combustor. Numerical results are compared with experimental data in terms of mean flow velocities, turbulent kinetic energy, and turbulent stresses. Numerical results clearly indicate that the RNG-based K-
turbulence model shows a significant improvement over a standard K-
model in predicting the turbulent flows with flow separation and swirl.
Numerical Study of Turbulent Swirling Isothermal and Spray-Combusting Flows
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 130~141
Numerical study of a confined, swirling, isothermal and spray-combusting flows has been presented. The pressure-velocity coupling in the Eulerian gas-phase equation is handled by the improved PISO algorithm. The droplet dispersion by turbulence is introduced by a Stochastic Separated Flow(SSF) model. The k-
turbulence model and the eddy dissipation model are employed to account for turbulence-combustion interaction. The detailed comparison with experimental data has been made for the isothermal jet swirling flows and the nearly monodisperse spray-combusting flow in the swirl combustor.
The Filtrational Characteristics of Magnetic Fibrous Polymeric Filter as an Oil Filter for Automotive
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 179~186
The magnetic fibrous polymeric oil filter for automotive was obtained by pneumoextrusion processing prepared from thermoplastic polymer(polyamide) containing magnetic particulate filer (Ba ferrite), and treated subsequently in a magnetic fields. Using an oil filter tester and particle quantifier, the dependence of filtrational characteristics of the magnetic oil filter on the parameters of mean pore sizes and magnetic properties were analyzed. Also experimental engine-bed test of oil filters was investigated. The magnetic fibrous polymeric filter was shown to possess a highly filtration efficiency in filtering the fine metal particles with increasing the magnetic force of filter element. In this study, we knew that efficiency of magnetic fibrous polymeric filter was dependent on the magnetic strength of the filter elements.
Analysis of Temprature and Thermal Stress Distribution of a DI Diesel Engine Cylinder Head(PART I)
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 187~196
In this study, 3-dimensional finite element model of a diesel engine cylinder head was made to accomplish heat transfer analysis and also thermal stress and deformation analysis. Heat release analysis and Nusselt-Reynolds correlations were applied to determine the convective boundary conditions which are required for heat transfer analysis to calculate temperature distribution. Thermal stress distribution was also investigated from heat transfer analysis results. Steady state temperature and heat flux were measured by using K-type thermocouples and then compared with numerical results to give a guarantee for the propriety of numerical analyses.
Steady Flow Characteristics of Four-Valve Cylinder Heads
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 197~205
The flow characteristics of five different 4-valve cylinder heads were investigated in a steady flow rig using laser-Doppler velocimetry. The tumble flow of each head with pentroof combustion chamber was quantified by nondimensional tumble number using a tumble adaptor. The formation of tumbling vortex was examined in an optical single-cylinder engine which has windows for in-cylinder LDV measurements. Tumble vortex ratio was estimated from the tumble flow measurement. The four-valve cylinder heads with pent-roof combustion chamber showed the tumble vortex from the intake process, which was investigated in the steady flow test. The tumble adaptor which converts the tumble into swirl flow was found to be feasible in predicting the tumble flow in the real engine. The tumble strength in the steady flow test coincides with that in the real engine experiment within 15%. It was found that the steady flow test on the four-valve cylinder heads provides the tip for a better design of cylinder head.
The Stress-strain Relationship of Glass Fiber Reinforced Thermoplastic Composite
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 206~214
Because of the wide variety of the composite materials, inherent variability in properties, and complex temperature and strain rate dependence, large strain behavior of these materials has not been well characterized. Large strain behavior under uniaxial tension is characterized over a range of temperatures and strain rates, and a modified simple linear viscoelastic model is fit to the observed data. Of particular importance is the strain rate and temperature dependence of these composites, and it is the primary focus of this study. The strain rate and temperature dependence is then used to predict limiting tensile strains, based on Marciniak imperfection theory. Excellent correlation was obtained between model and experiment and the results are summarized in maps of forming limit as a function of strain rate and temperature.
A Study on the Compression Process of Balanced Type Vane Pump for Electro-Hydraulic Power Steering
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 215~222
This paper reports on theoretical study of the compression process within balanced type vane pump for Electro-Hydraulic Power Steering(EHPS). Equations fo camring profiles are derived, then displacements, velocities, accelerations, and jerks are calculated. Vane side leakages, vane slit leakages, and rotor side leakages are considered and calculated. Numerical integration of flow equation is performed using 4th Runge-Kutta method. As a result of analysis, it is found that chamber pressure depends on rotational speeds, bulk modulus of fluid, notches, camring profiles, and positions of delivery port. Especially, the variation of notch area is the most important factor that prevents pressure from rapid rising.
A Study on Characteristics of Tool Wear and Surface Roughness in Face Milling of Automobile Parts
Transactions of the Korean Society of Automotive Engineers, volume 4, issue 5, 1996, Pages 223~230
The quality and productivity in machining automobile parts are influenced by various factors such as cutting conditions, vibration, and used tool. To improve the quality and productivity of the automobile parts(torsion beam), lots of research on the evaluation of tool life and control of surface roughness has been required. Therefore, the width of flank wear, cutting force, and surface roughness are monitored to analyse the characteristics of tool wear and surface roughness at different tools. This experimental investigation is mainly focused on the characteristics of the tool wear, tool life and surface roughness in multi-insert milling of automobile parts(torsion beam) by using uncoated tungsten carbide tool(WC), TiN coated tool, and cermet tool.