An axially grooved ammonia heat pipe was launched aboard an S-520 sounding rocket. The heat pipe is a 10mm (OD) x 330mm (length) circular aluminum pipe with twenty 0.5mm (width) x 1.0mm (depth) rectangular axial grooves, and is fixed along the rocket axis with the condensor top. About 300g of N-eicosane is employed as a phase change material in the heat sink section. The flight imposed three different levels of the acceleration on the heat pipe, large positive acceleration, small negative immediately after burnout and so called zero-gravity. The heat pipe dynamically responded to these conditions. Through the boosting period, the evaporator temperature went down by about 1.2 Cel compared with one-g performance. Then, after booster burnout, the partial dryout occured at the evaporator due to small negative acceleration resulted from the aerodynamic drag. The normal heat pipe operation was recovered when all three components of the acceleration diminished down to the order of 10(exp-3)-g or less and the heat pipe experienced zero-g condition for about 450 sec. (Wassmann)
Behavior of axially grooved heat pipe aboard a rocket
Verhalten von axial gerillten Waermeleitrohr an Bord einer Rakete
1982
7 Seiten, 7 Bilder, 1 Tabelle, 6 Quellen
Conference paper
English