Pulsating Heat Pipe in Hypergravity Conditions

Abstract

A closed-loop pulsating heat pipe made of a copper tube (1.1 mm/2 mm I.D./O.D.) and filled with FC-72 has been tested in a large-diameter centrifuge (LDC) of the European Space Agency in Noordwijk at different hypergravity levels up to 20 g, different heat input levels, and different orientations with respect to the gravity direction (vertical bottom heated and horizontal position). The results show that both in the horizontal and vertical orientation the device operation depends on the combined effect of gravity and heat input level. For the horizontal orientation, fluid stratification and the consequent thermal crisis occur at different acceleration levels depending also on the heat input power level and on the heating/gravity history. During the vertical operation, the pulsating heat pipe (PHP) thermal performance is slightly enhanced by the lower hypergravity levels (up to 3 g at 50 W, up to 4 g at 70 W, and up to 6g at 100 W), while two different local thermal crises affect the PHP thermal behavior at higher acceleration levels

Geometrical Shape of Pulsating Heat Pipe under Hyper Gravity Condition

“…Ma et al [5] in 2011 conducted experiments using a rotating table. The performance did not change up to a maximum acceleration of 10 g. Mameli et al [6] and Ayel et al [7] in 2015 tested the PHP during parabolic flight campaigns. They noted that hyper-gravity conditions of up to 2 g, resulted in the prevention of thermal instabilities after applying micro-gravity conditions.…”

Experimental Investigation of a Large Scale-oscillating Heat Pipe at Different Inclinations

“…Varying the effects of gravity on the OHP orientation has become one of the popular topics in the recent investigations (Mameli et al, 2014;Mameli et al, 2015;Ayel et al, 2015;Mangini et al 2017). The results of such studies show that both gravity and heat input level influence the device operation.…”