An experimental work on thermal features of the miniature revolving heat pipes

As the traditional rotating heat pipe, the condensate film is transported from condenser to evaporator by centrifugal force in the revolving heat pipe (RVHP), however, there is an eccentric distance between the rotational axis and its central axis. An experimental investigation is conducted on thermal features of the miniature revolving heat pipes (MRVHPs), at rotational velocities ranging from 1000 to 3000 rpm, and heat loads ranging from 2.5 to 30 W, the influence of the capillary structure is taken into consideration as well. The results show that the outer surface temperature of heat pipe wall decreases with the increases rotational velocity. The main axial temperature difference and the corresponding thermal resistance reduce as the rotational velocity increases. Based on the experimental data, a novel correlation of the Nusselt number on the condenser surface of the ordinary-wick MRVHP and the rotational Reynolds number is obtained. The results of the comparative experiments show that the capillary structure has contributed to the uniformity of circumferential temperature and evaporation heat transfer in MRVHPs, however, the main axial temperature difference and the corresponding thermal resistance are enlarged because of the existence of the capillary structure.