• Title/Summary/Keyword: 배경대비복사

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Analysis on Infrared Stealth Performance with Emissivity Controlled Aircraft Surface Structure at Various Background (항공기 적외선 스텔스 기술 적용을 위한 다양한 배경조건에서의 방사율 제어구조 성능 분석)

  • Bae, Munjang;Kim, Taehwan;Kim, Taeil;Jung, Daeyoon;Cho, Hyung Hee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.5
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    • pp.455-461
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    • 2016
  • Survivability of an aircraft has been greatly threatened by the development of a weapon system using infrared. Therefore, the infrared stealth technology is a very important technique to improve the survivability of an aircraft. In this study, the infrared signal of an aircraft was analyzed which corresponding to the aircraft surface temperature and environmental conditions with various surface conditions(especially emissivity changed). Based on the analyzed infrared signal, the optimized surface emissivity was suggested to reduce the average contrast radiance and contrast radiant intensity(CRI). In addition, we confirmed that the infrared contrast radiant intensity between the aircraft and the background can be minimized through an appropriately controlled surface emissivity of the aircraft at specific background.

Effect of Flight Altitude on Minimal Infrared Signature of Combat Aircraft (고도 변화에 따른 전투기 적외선 신호 최소 조건 분석)

  • Nam, Juyeong;Chang, Injoong;Lee, Yongwoo;Kim, Jihyun;Cho, Hyung Hee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.33 no.6
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    • pp.375-382
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    • 2020
  • Owing to the rapid development of infrared guided weapon systems, the threat to aircraft survivability is constantly increasing, and research on infrared stealth technologies are being conducted to ensure aircraft survival. In this study, we analyze the minimum infrared signature of an aircraft according to its flight altitude by considering the characteristics of infrared guided missiles, which detect the contrast signature between the aircraft and background. We conducted computational fluid dynamics simulations for the convective coefficient, and heat transfer simulations were performed considering convection, conduction, and radiation for flight conditions. Thus, we obtained the surface temperature distribution of the aircraft and analyzed the aircraft infrared signature based on the flow characteristics around it. Furthermore, the optimum emissivity for the minimum infrared signature was derived, and the effect of the infrared signature was analyzed when this optimum emissivity was applied to the fuselage surface for each flight condition.

Thermal Signature Characteristics of Clothed Human Considering Thermoregulation Effects (체온 조절 작용을 고려한 의복 착용 시의 인체 열상신호 특성 분석)

  • Chang, Injoong;Bae, Ji-Yeul;Lee, Namkyu;Kwak, Hwykuen;Cho, Hyung Hee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.2
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    • pp.109-116
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    • 2019
  • Survivability of soldiers has been greatly threatened by the development of thermal observation device(TOD). Therefore, infrared, especially thermal, stealth technology is applied to combat suit to avoid detection from TOD. In this study, prior to the thermal camouflage performance evaluation of combat suit, thermal signature characteristic from clothed the human body was analyzed considering the realistic condition for human surface temperature compared to that from unclothed human body. To get the realistic surface temperature distribution of human, thermoregulation and multi-layer skin structure model is applied to the human model. Based on temperature distribution, surface diffuse radiance in thermal range is calculated and by assuming the background conditions, contrast radiance intensity(CRI) characteristic of human body is analyzed. By wearing clothing, the CRI between background and human body became reduced in low emissive background but in high emissive background, the contrast is much more prominent. Therefore, this issue should be considered in design process of thermal camouflage combat suit.