Publication de 4 numéros par an
ISSN Imprimer: 2151-7975
ISSN En ligne: 2151-7991
THERMAL PERFORMANCE OF RE-ENTRANT GROOVE HEAT PIPE: DEPENDENCE ON ORIENTATION AND TEMPERATURE
RÉSUMÉ
When heat pipes are installed on a spacecraft, the spacecraft is, in general, designed so that the heat pipes are oriented horizontally during ground operation and kept at room or low temperature. These conditions are different from those assumed to be present when the heat pipe is charging. Therefore, we examined heat pipes performance under limited conditions. The performance of a re-entrant groove heat pipe was studied as a function of tilt angle and surrounding temperature, with particular focus on the tilt angle dependence in the low temperature/low heat input condition. The working fluid in the heat pipe was ammonia. The tilt angle of the heat pipe was varied between -1° and 90° (flux and reflux condition), and the surrounding temperature was set to 295, 233, and 213 K. The start-up character and the thermal conductance were found to depend on the tilt angle, the surrounding temperature, and the heat input. It was observed that heat rejection in the condenser was blocked by a liquid slug when the pipe was oriented horizontally in the high heat input condition at room temperature. At low surrounding temperature, the temperature of the heat pipe oscillated when the latter had a small tilt angle in the low heat input condition. The re-entrant groove heat pipe worked at all tilts angles and all surrounding temperatures.