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ISSN Online: 2688-7231

ISBN Online: 978-1-56700-524-0

Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
December, 17-20, 2021, IIT Madras, Chennai, India

Geyser Boiling in a Pulsating Heat Pipe Unit Cell

Get access (open in a dialog) DOI: 10.1615/IHMTC-2021.2490
pages 1651-1657

Resumo

The paper presents an experimental study performed over the geyser boiling in the unit cell of a vertical pulsating heat pipe (PHP) at different evaporator and condenser section temperatures. The oscillations of liquid plug in condenser, take-off of the liquid pool from evaporator bottom during geyser boiling, and coalescence of the ascending liquid pool with the oscillating liquid plug are recorded with the help of high speed cameras. The pressure fluctuations at evaporator bottom are recorded and it is found that geyser boiling is characterized by a pressure spike. The geyser boiling is observed to have a significant extent of aperiodicity and a lower condenser temperature increases its time period. It is found that thin film evaporation has neither pronounced nor negligible contribution towards geyser boiling. It has indeed a significant contribution during the post bubble-nucleation stage of geyser boiling. The geyser boiling is found to enhance the sustainability of oscillations by large momentum transfer from high speed liquid pool to the sluggish liquid plug. Also, the geyser boiling enhances the heat transfer by intermittently increasing the oscillation amplitude.