Thermal Behavior of Axial Groove Heat Pipe with Radiator under Gravity: Dependence of tilt angles



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46th International Conference on Environmental Systems


Axially grooved heat pipes (AGHPs) have been used as heat transfer devices of spacecraft. These AGHPs should be confirmed these thermal performance before the launch. When AGHPs are mounted on a spacecraft, the spacecraft is, in general, designed so that the heat pipes are oriented horizontally during ground operation. In some cases, heat pipes are installed so that they work in re-flux mode (bottom heat or thermosiphon mode). In addition, the ground test carried out not only at room temperature but also at low temperature because the temperature in orbit may become colder (ex. in a thermal vacuum test). We need to confirm the performance of start-up and reject heat transfer to understand the behavior of the heat pipe under the force of gravity at low temperature. We studied two kinds of AGHPs: The one has Ω shape grooves and the other has rectangular shape grooves. We focused on the dependence of the tilt angle against the horizontal plane on thermal performance in reflux mode surrounding at low temperature with or without radiator panel. Finally we compared simple AGHPs performance and that one installed on radiator panels. In the results that the AGHPs mounted radiator panels start-up character and temperature oscillation also depend on the tilt angle and surrounding temperature. We find that the temperature oscillation appeared only on the AGHPs. We will discuss the AGHPs thermal behavior included the reject heat system under 1G condition.


Japan Aerospace Exploration Agency
ICES201: Two-Phase Thermal Control Technology
Vienna, Austria
Hiroyuki Ogawa, Japan Aerospace exploration Agency, Japan
Yasuko Shibano, Japan Aerospace exploration Agency, Japan
The 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.


AGHPs, ground test, tilt angle, low temperature