• 제목/요약/키워드: Constant Worst Cold Case Condition

검색결과 4건 처리시간 0.021초

열해석에 의한 인공위성 추진시스템 열설계 (Thermal Design for Satellite Propulsion System by Thermal Analysis)

  • 한조영;김정수;이승우
    • 대한기계학회논문집B
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    • 제27권1호
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    • pp.117-124
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    • 2003
  • Thermal design fur satellite propulsion system has been performed. Overall design requirements and the constitution for propulsion system is described. To meet the thermal design requirements, both a primary and a redundant heater circuit, each with two thermostats placed in series, will protect each hydrazine-wetted components, even if one heater circuit fails to operate. Heater power is turned off if any one of these thermostats is opened at its higher setpoint. Thus, even if one thermostat is failed closed, the second thermostat will turn off the heater. All such components shall be insulated with MLI. Propulsion heater sizing based on the constant worst cold case condition is conducted through thermal analysis. All heaters selected fur propulsion components operate to prevent propellant freezing satisfying the thermal requirements for the propulsion subsystem over the worst case average voltage, i.e. 25 volts.

다목적실용위성 2호 추진계의 열설계 (Thermal Design for KOMPSAT-2 Propulsion System)

  • 한조영;김정수;이균호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.77-82
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    • 2001
  • Thermal design for KOMPSAT-2 propulsion system has been performed. Overall design requirements and the constitution for propulsion system is described. To meet the thermal design requirements, both a primary and a redundant heater circuit, each with two thermostats placed in series, will protect each hydrazine-wetted components, even if one heater circuit fails to operate. Heater power is turned off if any one of these thermostats is opened at its higher setpoint. Thus, even if one thermostat is failed closed, the second thermostat will turn off the heater. All such components shall be insulated with MLI. Propulsion heater sizing based on the constant worst cold case condition is conducted through thermal analysis. All heaters selected for propulsion components operate to prevent propellant freezing satisfying the thermal requirements for the propulsion subsystem over the worst case average voltage, i.e. 25 volts.

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인공위성 추진제 탱크의 열적 반응 및 민감도 해석 (Thermal Response and Sensitivity Analysis of Satellite Propulsion Tank)

  • 한조영;이균호;유명종
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2004년도 추계 학술대회논문집
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    • pp.131-136
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    • 2004
  • Thermal control of satellite propellant tank is achieved by patch heaters enabled by thermostat's behavior. It is important to attach the thermostat on the appropriate position of the propellant tank. However its position cannot be given with exact numerics because tank is spherical. Actually the position for thermostat is designated in relevant drawing approximately, therby, the engineer practices depending on his own experience and intuition. The sensitivity analysis for the position of thermostat is performed such that the influence on the thermal behavior and control of tank is examined quantatively. When assembling tank module, the reasonable performance on the thermal control is believed with possible human errors if the uncertainty in the position of thermostat is not quite large.

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써모스탯 위치변화에 대한 인공위성 추진제 탱크의 열적 반응 해석 (Thermal Response Analysis of Satellite Propulsion Tank with Thermostat Location Variation)

  • 이균호;한조영;최준민;문홍열
    • 한국항공우주학회지
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    • 제32권7호
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    • pp.126-132
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    • 2004
  • 위성 추진제 탱크의 열제어는 써모스탯에 의해 작동되는 히터를 이용해 수행된다. 적절한 위치에 써모스탯을 부착하는 것이 관건이지만 구형 탱크에서는 부착위치를 수치적으로 정확하게 부여하는 것이 불가능하다. 실제로는 도면에 대략적으로 위치를 제시한 후 작업자의 경험과 판단에 의존하여 써모스탯을 부착하는 것이 현실이다. 그러므로 써모스탯의 부착위치에 대한 민감도 해석을 수행함으로써 그에 따른 탱크의 열적 거동 및 열제어에 미치는 영향을 정량적으로 파악하였다. 실제 탱크 모듈 조립시 써모스탯의 부착위치에 대한 오차가 존재하더라도 설계 도면에 명시된 값보다 크게 벗어나지 않는 한 탱크의 열제어 성능은 충분히 보장되리라 판단된다.