Experimental investigation on the operating characteristics of a dual compensation chamber loop heat pipe subjected to acceleration field

摘要

High power and high local heat flux electronic devices employed in aircraft and spacecraft sustain the high acceleration condition in maneuvers and take-off stage. Loop heat pipe (LHP) are promising in dissipating high heat load to meet the increasing cooling needs. This article presents an experimental investigation on the operating characteristics of a dual compensation chamber loop heat pipe (DCCLHP) under elevated acceleration conditions. A centrifuge with a 2 m-long arm is used to provide the acceleration up to 7 g with four different acceleration directions. The heat load applied on the evaporator ranges from 80 W to 300 W. The typical performances in terrestrial were obtained and the influence of the different acceleration direction and magnitude on the operating characteristics was analyzed. Experimental results show that the change of the vapor liquid distributions induced by the acceleration force results in some specific operating characteristics of the DCCLHP. The operating temperature becomes lower as the effect of the acceleration force improves the liquid returning. The operation of the DCCLHP demonstrates the sensitive behavior to the acceleration direction at small heat load and insensitive behavior at large heat load. It was also found that the acceleration magnitude can alter the operating mode. A number of unstable phenomena are observed under both terrestrial gravity and elevated acceleration conditions. (C) 2015 Elsevier Ltd. All rights reserved.