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Passive Thermal management for avionics in high temperature environment

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this ppt is prepared from the research paper and this ppt is basically about the avionics systems.

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Passive Thermal management for avionics in high temperature environment

  1. 1. *Passive Thermal Management for Avionics in High Temperature Environment
  2. 2. • Avionics are the electronic systems used on aircraft, artificial satellites, and spacecraft. • Avionic systems include communications, navigation, the display and management of multiple systems. • The cockpit of an aircraft is a typical location for avionic equipment *
  3. 3. * *Under a program funded by the Air Force Research Laboratory(AFRL), Advanced Cooling Technologies(ACT) has developed a series of Passive Thermal Management techniques for cooling avionics.
  4. 4. * *The rejection of the waste heat generated by the electronics in the avionics to the surrounding environment, results in a significant ambient heat gain. *As a result this high temperature reduces the life of the electronics. *Heat must be transported to a sink. *The only viable sink is aircraft fuel, some times the fuel temperature can become too high to effectively cool avionics.
  5. 5. * *Two passive thermal approaches for avionics packages. 1. Heat Pipe Assemblies(To reduce the internal temperature gradient) 2. Loop Heat Pipe(to transport thermal energy to alternative sinks)
  6. 6. *Heat pipe assemblies were capable of reducing the internal temperature gradient by approximately 25 degree Celsius. *This reduction translates directly to an increase in the allowable sink temperature that will still provide sufficient cooling for the electronic components.
  7. 7. * *LHP was designed to transport thermal energy from the fuel to two heat rejection section. *Two heat rejection sections were necessary as aircraft sink condition can vary considerably throughout the flight. *Since these sinks can approach temperature much higher than the intended operating temperature of the LHP.
  8. 8. * *Two sinks that together were capable of providing heat rejection over the entire flight envelope. *Methanol was selected as the working fluid. *Stainless Steel was used for the evaporator body, compensation chamber and transport lines.
  9. 9. *
  10. 10. *Both condenser exchanged waste heat with Liquid Nitrogen(LN) *The flow of LN was controlled to maintain the sink temperature at the desired value. *Each condenser also had a surface exposed to an electric heater. *This allowed the sink temperature to be raised above the LHP vapor temperature.
  11. 11. *Heat pipes transport Heat by two phase flow of a working fluid *Liquid Phase *Vapor Phase

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