• Title/Summary/Keyword: 궤도 열 해석

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Thermal Characteristics Investigation of Spaceborne Mesh Antenna with Dual-parabolic Surfaces (이중막 구조를 적용한 우주용 전개형 메쉬 안테나의 열적 특성 분석)

  • Kim, Hye-In;Chae, Bong-Geon;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
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    • v.16 no.5
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    • pp.86-93
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    • 2022
  • Generally, a deployable solar panel is used primarily to achieve sufficient power output to perform the mission. However, temperature distribution on the antenna reflector may increase due to the shading effect induced by the presence of the deployable solar panels. Appropriate thermal design is critical to minimize the thermal deformation of the mesh antenna reflector in harsh on-orbit thermal environments to ensure remote frequency (RF) performance. In this paper, we proposed a dual-surface primary reflector consisting of a mesh antenna and a flexible fabric membrane sheet. This design strategy can contribute to thermal stabilization by using a flexible solar panel on the rear side of membrane sheet to reduce the temperature distribution caused by the deployable solar panel. The effectiveness of the mesh antenna design strategy investigates through on-orbit thermal analysis.

Thermal Design and On-Orbit Thermal Analysis of 6U Nano-Satellite High Resolution Video and Image (HiREV) (6U급 초소형 위성 HiREV(High Resolution Video and Image)의 광학 카메라의 열 설계 및 궤도 열 해석)

  • Han-Seop Shin;Hae-Dong Kim
    • Journal of Space Technology and Applications
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    • v.3 no.3
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    • pp.257-279
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    • 2023
  • Korea Aerospace Research Institute has developed 6U Nano-Satellite high resolution video and image (HiREV) for the purpose of developing core technology for deep space exploration. The 6U HiREV Nano-Satellite has a mission of high-resolution image and video for earth observation, and the thermal pointing error between the lens and the camera module can occur due to the high temperature in camera module on mission mode. The thermal pointing error has a large effect on the resolution, so thermal design should solve it because the HiREV optical camera is developed based on commercial products that are the industrial level. So, when it operates in space, the thermal design is needed, because it has the best performance at room temperature. In this paper, three passive thermal designs were performed for the camera mission payload, and the thermal design was proved to be effective by performing on-orbit thermal analysis.

Thermal Design and Analysis for Space Imaging Sensor on LEO (지구 저궤도에서 운용되는 영상센서를 위한 열설계 및 열해석)

  • Shin, So-Min;Oh, Hyun-Ung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.5
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    • pp.474-480
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    • 2011
  • Space Imaging Sensor operated on LEO is affected from the Earth IR and Albedo as well as the Sun Radiation. The Imaging Sensor exposed to extreme environment needs thermal control subsystem to be maintained in operating/non-operating allowable temperature. Generally, units are periodically dissipated on spacecraft panel, which is designed as radiator. Because thermal design of the imaging sensor inside a spacecraft is isolated, heat pipes connected to radiators on the panel efficiently transfer dissipation of the units. First of all, preliminary thermal design of radiating area and heater power is performed through steady energy balance equation. Based on preliminary thermal design, on-orbit thermal analysis is calculated by SINDA, so calculation for thermal design could be easy and rapid. Radiators are designed to rib-type in order to maintain radiating performance and reduce mass. After on-orbit thermal analysis, thermal requirements for Space Imaging Sensor are verified.

ON-ORBIT THERMAL ANALYSIS FOR THE GEOSTATIONARY OCEAN COLOR IMAGER OF A GEOSTATIONARY SATELLITE (정지궤도위성의 해양관측센서 임무 궤도 열해석)

  • Kim, Jung-Hoon;Jun, Hyoung-Yoll
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.135-141
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    • 2009
  • A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. According to the results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature is found slightly out its specification, therefore further detailed analyses should be continued on this element.

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Numerical Study on the Thermal Design of Lunar Terrain Imager System Loaded on the Korea Pathfinder Lunar Orbiter (시험용 달 궤도선의 광학탑재체 시스템 열설계에 대한 수치해석적 연구)

  • Kim, Taig Young;Chang, Su-Young;Heo, Haeng-Pal
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.4
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    • pp.309-318
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    • 2019
  • The thermal design of the Lunar Terrain Imager (LUTI) on the Korean Pathfinder Lunar Orbiter (KPLO) was performed and the soundness of the thermal design was verified by thermal analysis. The thermal environment of the lunar mission orbit should be reflected in the thermal design because the IR radiation of the lunar surface is important, unlike the earth orbit. The components or modules exposed to the outside of the satellite are insulated with MLI as much as possible, but the camera tube and the radiator are functionally exposed, so the thermal shield using the concept of radiation shape factor is mounted on the front to mitigate IR radiation. The IR emissivity is important in the front side of the radiator that receives little solar radiation, and components that are susceptible to thermal deformation such as the tube use a radiation heater to minimize the temperature gradient. Through the investigation of computational results, it was confirmed that the thermal design of LUTI is stable in various situations.

On-orbit Thermal Control of MEMS Based Solid Thruster by Using Micro-igniter (MEMS 기반 고체 추력기의 마이크로 점화기를 이용한 궤도 열제어)

  • Ha, Heon-Woo;Kang, Soo-Jin;Jo, Mun-Shin;Oh, Hyun-Ung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.9
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    • pp.802-808
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    • 2014
  • MEMS based solid propellant thruster researched for the purpose of an academic research will be verified at space environment through CubeSat program. For this, the temperature of the MEMS thruster should be within allowable operating temperature range by proper thermal control to prevent the ignition failure caused by ignition time delay and to guarantee the structural safety of the MEMS thruster in the low temperature. In this study, we proposed an effective thermal control strategy, that is to use micro-igniter as a heater and temperature sensor for active thermal control instead of using additional heater. The effectiveness of the strategy has been verified through on-orbit thermal analysis of CubeSats with MEMS thruster.

A study of Heat Analysis on Track Rubber Parts (궤도고무부품의 열해석에 관한 연구)

  • Kim, Young-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.9
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    • pp.117-122
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    • 1999
  • Track rubber parts has heat built-up as long as dynamic loading is applied from running tracked vehicles. Durability is required for rubber part to sustain the heat accumulation and heat exchange between rubber-metal assembly and environmental air and ground. For this research, the track assembly was divided into four parts i.e., bottom track shoe, upper track pad, pin busing and metal structure. Three rubber parts and metal structure were modelled and analyzed with MARC package program to obtain time-temperature data which was induced form mechanical work of tracked vehicles. heat accumulation data was obtained from special experiments under the room temperature of 25$^{\circ}C\;and\;35^{\circ}C$ to simulate the actual environmental conditions. From this research, it is cleared that the environmental temperature does not affect to the heat accumulation speed in rubber parts. Also, the heat built-up mechanism was clarified from the thermo-mechanical work based on numerical analysis and experiments.

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Numerical and Experimental Thermal Validation on Pogo-pin based Wire Cutting Mechanism for CubeSat Applications (큐브위성용 포고핀 기반 열선절단 분리장치의 열적 거동 분석 및 검증)

  • Min-Young Son;Bong-Geon Chae;Hyun-Ung Oh
    • Journal of Aerospace System Engineering
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    • v.17 no.2
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    • pp.94-102
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    • 2023
  • A nylon wire holding and release mechanism (HRM) has been widely used for deployable applications of CubeSat owing to its simplicity and low cost. In general, structural safety of solar panel with an HRM has been designed by performing structural analysis under a launch environment. However, previous studies have not performed thermal analysis for HRM in an on-orbit environment. In this study, Launch and Early Orbit Phase (LEOP) thermal analysis was performed to evaluate thermal stability of the mechanism in the orbital thermal environment of the pogo pin-based HRM applied to CubeSat. In addition, the effectiveness of the thermal design and performance of the pogo pin-based HRM were verified through a thermal vacuum test.

On-Board Black Body Thermal Design and On-Orbit Thermal Analysis for Non-Uniformity Correction of Space Imagers (영상센서의 비균일 출력특성 교정용 흑체의 열설계 및 궤도 열해석)

  • Oh, Hyun-Ung;Shin, So-Min;Hong, Ju-Sung;Lee, Min-Kyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.10
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    • pp.1020-1025
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    • 2010
  • On-board black body is used for radiation temperature calibration of spaceborne radiometers and imaging systems. The thermal design of black body proposed in this study is basically composed of heaters to heat-up the black body from low to high temperature during the calibration, heat pipe to transfer residual heat on the black body just after calibration to radiator on the S/C and heaters on the radiator to keep the certain temperature range of the black body during non-calibration. In the present work, the effectiveness of thermal design of on-board black body has been investigated by on-orbit thermal analysis.