• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.71-76
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• 2013

For a die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimize the casting layout design of an automotive Oil Pan_DX2E, Computer Aided Engineering (CAE) simulation was performed with two layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the filling process with two models, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflow. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system.

• Journal of the KSME
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• v.33 no.11
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• pp.951-956
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• 1993

우리나라 자동차 공업의 성장과 더불어 자동차용 공조기기 산업도 빠른 속도로 양적인 성장을 하여, 특히 자동차용 공조장치는 1992년 공조 관련 기기 총생산액의 약 40%를 차지했다. 자동 차용 공조장치는 압축기, 열교환기, 송풍팬 등의 주요 요소로 구성되어 있으며 이중에서 열교환 기는 공조 공간인 차실내의 쾌적성 향상, 구성 기기의 에너지 효율 향상등과 밀접한 관계가 있다. 이러한 자동차용 열교환기는 에너지 파동 이후 에너지와 자원의 절약에 대한 사회적인 요구에 부응하여 보다 고성능, 소형화, 경량화를 요구하게 되었다. 최근에는 전세계적으로 지구 환경문 제에 대한 관심이 고조되어 에너지 자원의 효율적인 이용, 환경 보호 등을 포함하는 광범위한 열문제를 고려할 필요가 있게 되었다. 특히 자동차용 열교환기는 산업용이나 가정용 고조 시스 템의 열교환기와는 달리 설치공간의 제약, 부하 변동폭의 증대 등으로 인해 고성능, 소형화가 요구되며 또한 자동차의 연비향상을 목적으로 경량화가 요구됨과 동시에 환경 문제의 발단인 대체 프레온 대응 등 해결해야 할 기술적인 과제가 많다. 이러한 상황을 감안하여 대표적인 자 동차용 열교환기의 기술 동향을 소개하고자 한다.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.4
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• pp.307-313
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• 2003

A technique for the design of cooling tower fans with sweep is presented. This technique is developed using the equations for the one dimensional inviscid flow through the fan blade, the empirical equations, and the experimental correlations. A parabolic function is used to generate a sweep of the fan. Design data for the fan and the balde can be obtained for a given flow rate and a pressure rise. Also, the present method is used to construct the three dimensional model for the designed fan. Design data and the model show general characteristics of the axial propeller fan.

• Journal of Industrial Technology
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• v.34
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• pp.15-20
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• 2014

Recently, PMSMs(Permanent Magnet Synchronous Motors) have become increasingly popular in various high-performance motor drive applications. However, the high-performance drive of PMSMs needs a position sensor such as a resolver, which increases not only the price of the system but also reduces the system reliability. This paper is on the implementation of sensorless control of a SPMSM, which drives a fan for cooling in appliances. In this paper, the rotor position for high-performance drive of a SPMSM is derived from back electromotive force (EMF) information proportional to the rotor speed. Also, the initial rotor position information for start-up is estimated from a saturation phenomenon of inductance. The validity of the proposed sensorless drives was confirmed by the experiment on the SPMSM drive systems for cooling fans of refrigerators and laptop computers.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.12-12
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• 1998

국제 공동 가스터빈 엔진 개발 프로그램인 ASE120 사업은 항공기용 터보팬 엔진을 Low Emission 산업용 엔진으로의 개조사업으로서 현대우주항공, AlliedSignal, AIDC(대만), SPHT(대만) 등이 참여하고 있다. 본 사업을 통한 주요 개조 부품인 연소기의 경우, 산업용 엔진의 특성상 장시간의 수명이 보장되어야 하고 Dry Low NOx 연소실 형태로 배기가스 규제의 요구조건을 만족하여야 하므로 일반 항공기용 연소기와 구조적으로 첨예한 변화가 발생하여 구조 및 수명해석을 통한 구조적 안전성과 요구 수명에 대한 평가가 절대적으로 요구되었다. 당 엔진의 요구수명은 30년으로 cold section part의 경우 180,000시간, hot section의 경우 90,000시간의 수명을 목표로 개발되었으며, 연소기 최적설계를 위해 구조/수명 해석결과가 개발과정 중 설계에 지속적으로 반영되어 추진되었다. 연소기의 구조해석은 해석용 tool로서 ANSYS53을 활용하였고 수명예측은 AlliedSignal사의 Material Database 및 Inconel사 재질 data를 근간으로 수행하였다.

• IE interfaces
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• v.13 no.4
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• pp.717-724
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• 2000

In this paper, an integrated system of optimal design, performance evaluation, and die design and manufacturing of axial fans for cooling tower is presented. The design and performance evaluation are developed based on three dimensional flow analysis so as to ensure low noise and high efficiency. The methodologies are implemented on computer as a GUI system including 3-D surface modeling and 2-D drawing file output modules. The CAD/CAM system is engaged to design the die and generate NC tool path, but the processes are also automated and integrated into the system by means of a part program coded from the design data. It is shown that the newly developed fans have superior performance and shortened lead-time compared to the existing dead-copied fans.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.241-246
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• 2018

The engine cooling system is a device that keeps the temperature of the engine room at a proper level by driving the cooling fan when the engine room temperature that occurs during driving is above a certain temperature. Recently, the vehicle cooling system has been changed to electronic system. Therefore, in this paper, we will analyze the clutch operation characteristics for designing a superior electronic fan clutch. For this purpose, an electronic fan clutch was designed and a test bed for performance evaluation was constructed and analyzed.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.41-45
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• 2018

As the size of semiconductor chip shrinks, the electronic industry has been paying close attention to fan-out wafer level packaging (FO-WLP) as an emerging solution to accommodate high input and output density. FO-WLP also has several advantages, such as thin thickness and good thermal resistance, compared to conventional packaging technologies. However, one major challenge in current FO-WLP manufacturing process is to control wafer warpage, caused by the difference of coefficient of thermal expansion and Young's modulus among the materials. Wafer warpage induces misalignment of chips and interconnects, which eventually reduces product quality and reliability in high volume manufacturing. In order to control wafer warpage, it is necessary to understand the effect of material properties and design parameters, such as chip size, chip to mold ratio, and carrier thickness, during packaging processes. This paper focuses on the effects of thickness of chip and molding compound on 12" wafer warpage after PMC of EMC using finite element analysis. As a result, the largest warpage was observed at specific thickness ratio of chip and EMC.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.812-818
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• 2003

This paper presents a developed outside rotor type induction motor for the fan. Nearly all of the induction motors consist of two parts, rotor and stator, and the position of rotor is generally inside of stator. However, the rotor of the developed induction motor is located outside of stator. It is believed that the outside rotor type induction motor is suitable for the fan due to its large inertia, that is, it is considered that the change of air flow rate resulting from input power or load fluctuation is reduced. In this paper, the two tests which are suitable to obtain the electrical parameters of the outside rotor type induction motor were described, then various parameters of outside rotor type induction motor were measured. These are the locked rotor test and no load test. By using these tests, it was possible to determine the parameters which are presented in the steady-state equivalent-circuit of the outside rotor type induction motor. Load test of induction motor was carried out using a dynamometer and the torque-speed curve was obtained. It is believed that the results of this paper can be used for the development of the outside rotor type induction motor.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.217-225
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• 2023

The willingness of online music users to pay is the key to the protection of music copyright and the sustainable development of the industry. This paper aims to study the influencing factors of online music users' willingness to pay based on exploratory analysis. Based on the theory of customer perceived value, the unified theory of technology acceptance and use, and the theory of fan enthusiasm, the research model is constructed. Validate the obtained 583 valid data. Through analysis, I got that perceived value, interpersonal influence, fan enthusiasm, and personal payment awareness directly affect online music users' willingness to pay; practical value and hedonic value have a positive impact on perceived value, and the impact of economic cost and compilation cost has not reached a significant level; Online word-of-mouth negatively moderates the impact of perceived value on users' willingness to pay for music. Music platforms can formulate operating policies based on this.