Experimental Investigations on the Effect of Influencing Parameters on Operating Regime of Closed Loop Pulsating Heat Pipe
Thermal management drives real life applications which involve heat generation. Closed Loop Pulsating Heat Pipe (CLPHP) is a
two-phase passive device to provide a key solution for effective thermal management due to its excellent heat transfer capability
and efficiency. Operating regime of a CLPHP is restricted between the start up and critical heat flux (dry out limitation). Both the
heat fluxes are affected by numerous parameters such as a number of turns, filling ratio, heat input and orientation etc. The
experimental set up for 6-turn and 9-turn CLPHP of 2 mm copper tube is developed to investigate the influence of a number of
turns, filling ratio, heat input and orientation on the onset and intensity of pulsations (startup) as well as dry out phenomena.
Water is used as working fluid. Filling ratio (FR) is varied as 25%, 35%, 50%, 65% and 75%. Heat input is set in the range of 10-200 Watt involving 6-turn and 9-turn CLPHP. Thermal resistance is calculated as a performance parameter for each experimental run. The operating regime map is developed to identify start-up and dry out mechanism for a 6-turn and 9-turn CLPHP. FR of 50% and 9-turn CLPHP are observed to perform better with all orientations compared to 6-turn CLPHP.