• Journal of Mechanical Science and Technology
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• 제16권7호
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• pp.975-985
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• 2002

This paper deals with theoretical model developed for analyzing the heat transfer of automotive cooling systems. The model has a modular structure which links various cooling system submodels. From the model, heat transfer rate of automotive cooling systems can be predicted, providing useful information at the early stages of the design and development. The aim of the study is to develop a simulation program for automotive cooling system analysis and a performance analysis program for analyzing heat exchanger. Heat release rate from combustion gas to coolant through the cylinder wall in engine cylinder was analysed by using an engine cycle simulation program. In this paper, details of each submodel are described together with the overall structure of the vehicle model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.584-587
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• 1992

Because linear motor directly drives linear motion, it does not need conversion equipment such as belt and gear. Especially linear pulse motor provide more precise positioning and large force of linear pulse motors. As current manufacture technic of linear pulse motor is much to be desired at home. This motor lay out to make use of computer aided design program, In this paper the experimental motor is 2-phases 4-poles hybrid pulse motor which has teeth per pole Simulation program is divided its function into 4 parts - air gap permeance analysis, permanent magnet & non-linear core operating point determine, winding configuration, leakage flux analysis. It is possible to make motor static and magnetic characteristics for this simulation program. Also, by varying input parameters of the program, experimental motor is to be compared to motor characteristics.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.50-59
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• 1996

The computer simulation program that calculates the transient heat load transferred to a passenger vehicle has been developed. Method for modeling mathematically various kinds of the heat load was presented and the derived equations were solved numerically. To find out the accuracy of the simulation program, the correlation of experimental and analytical results was demonstrated. By using this program, the typical characteristics about temperature distribution and instantaneous or of vehicle body color, material of glass, air-conditioning capacity, driving direction, and speed. Under a steady-state condition, the ratios of the heat load, resulting form vehicle body, glass, and interior part, were 35%, 29%, and 36%, respectively.

• 오토저널
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• 제8권1호
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• pp.75-86
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• 1986

This paper describes a simulation program of intake and exhaust processes in a 4-stroke S.I. engine and also studies the relationship among various engine parameters under different engine speed and load conditions. This simulation program includes the engine cylinder model for the intake and exhaust processes and its formulation and evaluates the system characteristics such as inlet mass, pumping work and residual gas in the cylinder-which influence on power output, fuel economy and exhaust emissions. In order to evaluate the accuracy of the simulation program, predicted results were compared with the experimental data obtained on the 4-stroke, 4-cylinder gasoline engine and satisfactory agreement was obtained.

• 설비공학논문집
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• 제11권4호
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• pp.499-510
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• 1999

A computer program was developed for simulating performance(capacity, power consumption and etc.) of air-conditioners using compressor, fin-tube heat exchanger and capillary tube. The program consists of five modules, condenser, evaporator, compressor, capillary tube simulation modules and properties modules of refrigerant and moist air, The present program is focused on R22 only, however can be easily extended for other refrigerants such as R407C and R410A just by adding property modules. The compressor simulation module utilizes performance maps supplied by manufacturers-map-based model. The condenser and evaporator simulation modules are modeled using tube-by-tube method. Simulation results(capacity and power consumption) were compared with calorimeter test results of actual air-conditioners of window and split types, where more than 82% of the data lied within ${\pm}5$% of the predicted results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.395-396
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• 2008

There is difficulty in predicting the program efficiency of NOR type nonvolatile memory device adopting channel hot electron injection (CHEI) as program operation mechanism accurately since MOSFET on SOI has floating body. In this study, the dependence of program efficiency for SOI nonvolatile memory device of 200 nm channel length on SOI depletion conditions, partial depletion and full depletion, was quantitatively investigated with the aid of numerical device simulation [1].

• 대한가정학회지
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• 제30권4호
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• pp.1-13
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• 1992

A computer simulation method for textile designs was developed using a generic-purpose graphics program, LUMENA and its results were applied for costume design simulation. Its design performance was comparable with those using specialized design package programs which are in general very expensive. Three areas of textile design, print pattern design, weaving design, and knitting design, were covered. In the print pattern design simulation, a gird network library was constructed by using basic methods of repeat, and a pattern library by scanning existing print patterns. Through the modification and synthesis of library patterns, many new print patterns could be obtained. In the weaving design simulation, a thread library and a draw-down library were constructed. Using them, simulations of woven textile structures were carried out. In the knitting design simulation, a stitch library and a detail library were made from various types of knit stitch and detail drawings of knit costume, respectively. They were used to make structural knitting patterns and jacquard knitting designs. Using those simulated textile designs, costume design simulation was carried out.

• 소성∙가공
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• 제14권8호통권80호
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• pp.675-680
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• 2005

This study was aimed at the design of the dies for the automobile part for the engine oil leakage prevention using the computer simulation to shorten the period of production, on the basis of the process planning which was designed by the field experts. In the computer simulation,'eesy-2-form' of 2D FEM simulation package and 'eesy-DieOpt' have been used, which are the commercial process analysis and die design program. Through the simulation of 'eesy-2-form', we could know the propriety of the forming process, the inner pressure of the die and the suitable fitting pressure between the insert and the sleeve which was not showing any positive tangential stresses in the insert. Through the simulation of 'eesy-DieOpt', we could know the number of the stress ring, the diameter ratios, the stresses of the die, the shrink fitting tolerance and temperature in the condition of the already determined maximum outer die diameter of the multi-stage former. The validity of the die design using the computer simulation was analyzed by the experiments and the results were satisfactory. As the results of this study, the new and easy die design system for cold forging has been developed.

• Journal of Biosystems Engineering
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• 제14권1호
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• pp.1-7
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• 1989

This study was carried out to develop a system and methodology to simulate the engine load variation occuring during agricultural field operations for a laboratory engine test. The system consisted of an electric dynamometer, an Apple II microcomputer, and a data acquisition and control system. Several pieces of instruments were utilized to measure various engine performance data. Both engine torque and engine speed were fully controlled by a computer program. The dynamic characteristics of the system were analyzed through a series of tests and the limitations on the load simulation test were presented. The results of the study are summarized as follows: 1. Engine speed and toque were controlled by a computer program. The use of a stepping motor and reduction gears enabled engine speed be controlled within 1 rpm. 2. The natural frequency of the dynamometer-engine system was found to be around 5 Hz, at which the load simulation would be impossible because of resonance. 3. For the harmonic inputs with the frequencies above the natural frequency, the signal attenuated too much and therefore the load simulation was impossible. 4. The step response of the system showed an overshoot of 24.5 percent and the settling time for 5 percent criterion was around 3 seconds. 5. When actual field test data are utilized for load simulation, a low-pass filter should be included to attenuate the frequency components around and above the natural frequency.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.119-128
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• 2001

Recently safety systems for the commercial vehicle have been rapidly developed. However, we still have many problems in the vehicle stability and the braking performance. Especially, a commercial vehicle may meet a dangerous braking condition when the vehicle is lightly loaded or empty and the road is wet or slippery. To design the air brake system for commercial vehicles, since the air brake system has many design variables, there must have been intensive researches on a method how to prevent dynamic instability and how to maximize the vehicle deceleration. In this study, mathematical models about an 8$\times$4 vehicle and an air brake system including an ABS controller have been constructed for computer simulation. Also, simple examples are applied to show the usefulness of the computer program. Designers can use this simulation program for understanding the braking characteristics of 8$\times$4 commercial vehicles such as trajectory, braking distance, longitudinal deceleration, lateral deceleration, and yaw rate on various road conditions.