A novel double pipe pulsating heat pipe design to tackle inverted heat source arrangement

Traditional pulsating heat pipe with fewer turns is functional only when the heat source is placed at the bottom while the heat sink is on top. This study proposes a novel design having alternative double-pipe tube diameter with some extra open connections of these double-pipes. By introducing extra un-balanced pressure force, capillary force and gravity force, the PHP can be easily starting up even for an opposite heat source/sink arrangement while the conventional single tube design fails to start up with this opposite arrangement. The thermal resistance of double pipe PHP can be lowered to 0.0729 W/K with an effective thermal conductivity of 12,603 W/m·K when the heat source is placed on top. Yet the thermal resistance for the proposed double pipe design is only half of the single tube design.