• Title/Summary/Keyword: 적외선 피탐지

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Infrared Reflector Design using the Phase Field Method for Infrared Stealth Effect (적외선 피탐지를 위한 페이즈 필드법 기반의 적외선 반사층 설계)

  • Heo, Namjoon;Yoo, Jeonghoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.1
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    • pp.63-69
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    • 2015
  • In this paper, infrared reflector design targeting infrared stealth effect is presented using structural optimization based on the phase field method. The analysis model was determined to accomplish the design that an incident infrared wave was reflected to a desired direction. The design process was to maximize the objective value at the measuring domain located in a target region and the design objective was set to the Poynting vector value which represents the energy flux. Optimization results were obtained according to the variation of some parameter values related to the phase field method. The model with a maximum objective value was selected as the final optimal model. The optimal model was modified to eliminate the gray scale using the cut-off method and it confirmed improved performance. In addition, to check the desired effect in the middle wave infrared range(MWIR), the analysis was performed by changing the input wavelength. The finite element analysis and optimization process were performed by using the commercial package COMSOL combined with the Matlab programming.

Research for Actively Reducing Infrared Radiation by Thermoelectric Refrigerator (열전소자를 이용한 적외선 방사량 감소 기술에 관한 연구)

  • Kim, Hoon;Kim, Kyomin;Kim, Woochul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.3
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    • pp.199-204
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    • 2017
  • We introduced a technology for reducing infrared radiation through the active cooling of hot surfaces by using a thermoelectric refrigerator. Certain surfaces were heated by aerodynamic heating, and the heat generation processes are proposed here. We calculated the temperatures and radiations from surfaces, while using thermoelectric refrigerators to cool the surfaces. The results showed that the contrast between the radiations of certain surfaces and the ambient environments can be removed using thermoelectric refrigerators.

Design of Light Trapping System of Thin Film Solar Cell Using Phase Field Method (페이즈 필드법을 이용한 박막형 태양전지의 광포획층 설계)

  • Heo, Namjoon;Yoo, Jeonghoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.9
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    • pp.973-978
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    • 2014
  • This study focused on the design of the reflecting layer of a light trapping system fora thin film solar cell using topology optimization based on the phase field method. Therefore, incident light was caused to propagate in the desired direction by reflecting it from this layer, which is the design domain. The same method was applied to the conceptual design of an infrared stealth structure in near infrared range. The results using the phase field method were compared with those using the density method. The design objective was to maximize the Poynting vector value representing the energy flux, which was measured in a measuring domain to control the reflected wave direction. A finite element analysis and optimization process were performed using the commercial package COMSOL combined with the MATLAB programming.

Thermal Environment Evaluation of Wooden House Using Infra-red Thermal Image and Temperature Difference Ratio (TDR) (적외선열화상과 온도차비율법을 이용한 목조 주택의 열환경평가)

  • Chang, Yoon-Seong;Eom, Chang-Deuk;Park, Jun-Ho;Lee, Jun-Jae;Park, Joo-Saeng;Park, Moon-Jae;Yeo, Hwan-Myeong
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.6
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    • pp.518-525
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    • 2010
  • Infrared (IR) thermography which is the technique for detecting invisible infrared light emitted by objects due to their surface thermal condition and for producing an image of the light has been applied in various field without damaging the objects. It also could be used indirectly to examine the inside of an object. In this study, insulation property of wooden house in Korea Forest Research Institute (KFRI) was evaluated with according to "Thermal performance of building - Quantitative detection of thermal irregularities in building envelopes - infrared method (KS F 2829)". This method uses "Temperature Difference Ratio (TDR)" between outdoor wall surface and indoor wall surface of wooden building for evaluating its thermal performance. The thermal performance of a room on the 2nd floor of the wooden house was focused in this study and IR thermography on the indoor and outdoor surface of the house was captured by IR camera. Heat loss from the corner and the window of the wooden house as well as wall of the house was quantitatively evaluated and the invisible heat loss in the wall was detected. It is expected that the results from this study could contribute to improve the wooden building energy efficiency.