• Title/Summary/Keyword: Thermal Field

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Vibration Analysis of Composite Cylindrical Shells Subjected to Electromagnetic and Thermal Fields with Different Boundary Conditions (경계조건에 따른 자기장 및 열하중을 받는 복합재료 원통셸의 진동해석)

  • Park, Sang-Yun;Kim, Sung-Kyun;Choi, Jong-Woon;Song, Ohseop
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.10a
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    • pp.653-660
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    • 2012
  • In this paper free vibration analysis of symmetric and cross-ply elastic laminated shells based on FSDT with two different boundary conditions(C-C, S-S) was performed through discretization of equations of motion and boundary condition. Model of laminated composite cylindrical shells subjected to a combination of magnetic and thermal fields is developed via Hamilton's variational principle. These coupled equations of motion are based on the electromagnetic equations (Faraday, Ampere, Ohm, and Lorenz equations) and thermal equations which are involved in constitutive equations. Variations of dynamic characteristics of composite shells with applied magnetic field, temperature gradient, and stacking sequence for each boundary conditions are investigated and pertinent conclusions are derived.

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An Analysis of Diesel Engine Cylinder Block-Liner-Gasket-Head Compound by Finite Element Method (유한요소법을 이용한 디젤 엔진의 실린더블록-라이너-가스킷-에드 구조물에 대한 해석)

  • 김주연;안상호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.3
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    • pp.147-158
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    • 1997
  • This paper presents the analysis technique and procedure of main engine components-cylinder block, cylinder liners, gasket and cylinder head-using the finite element method, which aims to assess mainly the potential of lower oil consumption in a view point of engine design and to decide subsequently the accuracy of engine design which was done. The F.E. model of an engine section consisting of one whole cylinder and two adjacent half cylinders is used, whereby the crankcase is cut off at the block bottom deck. By means of a 3-dimensional F.E. model-including cylinder block, liners, gasket, cylinder head, bolts and valve seat rings as separate parts a linear analysis of deformations and stresses was performed for three different loading conditions;assembly, thermal and gas loads. For the analysis of thermal boundary conditions also the temperature field had to be evaluated in a subsequent step.

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Field Enhanced Rapid Thermal Process for Low Temperature Poly-Si TFTs Fabrications

  • Kim, Hyoung-June;Shin, Dong-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.665-667
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    • 2005
  • VIATRON TECHNOLOGIES has developed FE-RTP system that enables LTPS LCD and AMOLED manufacturers to produce poly-Si films at low cost, high throughput, and high yield. The system employs sequential heat treatment methods using temperature control and rapid thermal processor modules. The temperature control modules provide exceptionally uniform heating and cooling of the glass substrates to within ${\pm}2^a\;C$. The rapid thermal process that combines heating with field induction accelerates the treatment rates. The new FE-RTP system can process $730{\times}920mm$ glass substrates as thin as 0.4 mm. The uniform nature of poly-Si films produced by FE-RTP resulted in AMOLED panels with no laser-Muras. Furthermore, FE-RTP system also showed superior performances in other heat treatment processes involved in poly-Si TFT fabrications, such as dopant activation, gate oxide densification, hydrogenation, and pre-compaction.

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A Study on the Thermal Environmental Analysis and the Application of Radiant Floor Cooling in Apartment Building (공중주택의 열환경분석과 바닥복사냉방의 적용에 관한 연구)

  • 김용이;김광우
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.6
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    • pp.541-548
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    • 2001
  • The objective of this study is to analyze the possibilities and considerations for the application of the radiant floor cooling system by analyzing the problems of a conventional cooling system through field tests and thermal performance simulations of the radiant floor cooling in an apartment building. The results are as follows. (1) Problems of he conventional cooling system with PAC()packaged air conditioner)'s include draft, local discomfort, and excessive electrical peak demand. (2) According to the measurement during the cooling and intermediate seasons, the floor surface temperatures which are experienced at the time of cooling with PAC\`s and during intermediate season are similar to the temperatures for radiant floor cooling. (3) The radiant floor cooling system is applicable to apartment buildings during the cooling season, especially on hot and clear days.

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Wide-angle optical design using high-resolution uncooled thermal detector

  • Lee, Jonghoon
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.11
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    • pp.31-37
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    • 2017
  • In this paper, we propose efficient design and construction of an infrared wide angle optical system with low distortion utilizing a high resolution detector for automobile application. The operational convenience and the recognition ability have been improved significantly by applying the high resolution uncooled thermal detector with wide angle optical design. The active ahtermalization mechanism is implemented so that the adjustment of the optical component of the system is to be made automatically according to the temperature change by motorized control. The modulation transfer function (MTF) is about 50% at the Nyquist frequency close the diffraction limit. The distortion is less than 5% at the edge field. As a result, a high-resolution uncooled thermal optical system with wide field of view (FOV) is assembled, aligned and its performance is tested successfully.

Analysis of the Thermal Environment and Natural Ventilation for the Energy Performance Evaluation of the Double Skin System during the Summer (이중외피 시스템의 에너지성능평가를 위한 하절기 열환경 및 자연환기 분석)

  • Eom, Jung-Won;Cho, Soo;Huh, Jung-Ho
    • Journal of the Korean Solar Energy Society
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    • v.22 no.4
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    • pp.68-76
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    • 2002
  • This paper discusses thermal and ventilation performance which might be caused by the adoption of one of specific building facade techniques, Double Skin System(DSS). One building with a prototypical DSS was selected and systematically investigated through field monitoring and computer simulation techniques. A network model of ventilation was successfully made using COMIS to evaluate ventilation performance of the system which can hardly be done by field measurements. Various operating conditions of air conditioning on/off and window opening were implemented in this type of building. Through the appropriate operation of the DSS in summer, simulation-based and experimental results implicate that it can lead to cooling energy savings.

Field Test for a Biological Nitrogen Treatment System with Low Temperature Solar Thermal Energy (저온 태양열을 이용한 생물학적 오수 처리 장치 실증 실험)

  • Chung, Mo;Lee, Dong-Won
    • Journal of the Korean Solar Energy Society
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    • v.28 no.2
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    • pp.34-41
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    • 2008
  • A low-temperature solar thermal system assisting a biological nitrogen treatment reservoir was designed and field-tested. A large tank whose temperature was maintained at about $25-30^{\circ}C$ to enhance the performance of a biological nitrogen treatment process was heated by an array of flat plate solar collectors. Test results revealed that the overall collector efficiency was above 50% for the most cases tested. This high efficiency was possible owing to the relatively low collector temperature that can be traced back to the reservoir temperature. A substantial enhancement in nitrogen treatment was observed as a result of maintaining the reservoir temperature higher.

The coupling field analysis of a thermal transfer phenomenon by an magnetic field (자계 분포시 열유동 현상 분석을 통한 결합계 해석)

  • Son, Rak-Won;Jang, Kwang-Yong;Bae, Jae-Nam;Kim, Sung-Ju;Choi, Sung-Gil;Ju, Lee
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.862-863
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    • 2007
  • In this article, we researched the characteristics of heat transfer of the bimetal for over-current protection device. Bimetal consists of two metals which have a different thermal expansion coefficient. To analyze the heat transfer characteristics, by using a bimetal which has a single metal, we analyzed the temperature distribution when bimetal acts a switch. As usual, heat source is applied to the bimetal. But, in the over-current protection switch, the current become heat source. So, by using the current as source, we performed the magnetic analysis and thermal analysis together.

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Biological Waste Water Treatment with Solar Thermal Energy (저온 태양열 이용 생물학적 오수 처리)

  • Chung, Mo;Lee, Dong-Won;Kim, Jeong-Bae;Yoon, Eung-Sang;Byun, Moo-Ryong;Byun, Moon-Won
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.559-562
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    • 2006
  • A low-temperature solar thermal system assisting a biological nitrogen treatment reservoir was designed and field-tested. A large tank whose temperature was maintained at about $25{\sim}30^{\circ}C$ to enhance the performance of a biological nitrogen treatment process was heated by an array of flat plate solar collectors. Test results revealed that the overall collector efficiency was above 50% for the most cases tested. This high efficiency was possible owing to the relatively low collector temperature that can be traced back to the reservoir temperature. A substantial enhancement in nitrogen treatment was observed as a result of maintaining the reservoir temperature higher.

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Transient wave propagation in piezoelectric hollow spheres subjected to thermal shock and electric excitation

  • Dai, H.L.;Wang, X.
    • Structural Engineering and Mechanics
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    • v.19 no.4
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    • pp.441-457
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    • 2005
  • An analytical method is presented to solve the problem of transient wave propagation in a transversely isotropic piezoelectric hollow sphere subjected to thermal shock and electric excitation. Exact expressions for the transient responses of displacements, stresses, electric displacement and electric potentials in the piezoelectric hollow sphere are obtained by means of Hankel transform, Laplace transform, and inverse transforms. Using Hermite non-linear interpolation method solves Volterra integral equation of the second kind involved in the exact expression, which is caused by interaction between thermo-elastic field and thermo-electric field. Thus, an analytical solution for the problem of transient wave propagation in a transversely isotropic piezoelectric hollow sphere is obtained. Finally, some numerical results are carried out, and may be used as a reference to solve other transient coupled problems of thermo-electro-elasticity.