Investigation of gravitational effects on the performance of variable conductance heat pipe.

Abstract

A variable conductance heat pipe with a length to diameter ratio of 96 to 1 was designed and constructed. The performance characteristics of both the conventional and gas loaded variable conductance modes of operation were studied. Particular emphasis was placed upon investigating the gravitational effects in the variable conductance mode. Heat inputs were varied from ten to fifty watts for horizontal and vertical operating positions. Methanol was used as the working fluid with either helium or krypton used as the non-condensible gas. Condenser temperature profiles and liquid crystal pictures, showing the effects of gravity, are presented for the various operating modes.