Effect of artificial cavities on the thermal performance of pulsating heat pipes

Abstract

In this study, the effects of pulsating heat pipes(PHPs) with artificial cavities on thermal performance and flow characteristics were investigated. Using MEMS techniques, silicon-based MPHPs with artificial cavities inside the channel were fabricated. The MPHP had rectangular channels which were engraved on a silicon wafer with a thickness of 1mm. The width and height of the micro-channels are 1 mm and 0.5 mm. The etched micro-channels were covered with Pyrex glass with a thickness of 1mm using anodic bonding. 4 different cases of PHP with artificial cavities were fabricated. PHPs with artificial cavities promoted nucleation and showed early startup. Furthermore, the effects of the size of the cavities on the thermal performance of PHPs were investigated. As the size of the cavities increased, early startup was observed. Moreover, activated artificial cavities increased the amplitude of displacement of the meniscus to enhance the thermal performance of the PHPs. Artificial cavities decreased the startup temperature and temperature during normal operation.