Boiling in a two-phase closed thermosyphon under horizontal vibration

A two-phase closed thermosyphon is a wickless and passive heat transfer device. In the thermosyphon, working fluid vaporizes in the lower evaporator section, and then the vapor condenses in the upper condenser section and returns to the evaporator section by gravitational force. Thermosyphons can be widely used for industrial applications, including cooling of electrical devices, batteries, and avionics equipment. These applications, however, may be encountered in diverse dynamic circumstances such as translation, rotation, and vibration. As a first step to make a thermosyphon function properly and improve its heat transfer performance under dynamic conditions, we experimentally investigate boiling patterns of the thermosyphon, when it is subjected to horizontal vibration, by varying the amplitude and frequency of vibration, heat input, and filling ratio. A new parameter which characterizes the intensity of vibration is introduced to determine the effect of horizontal vibration on phase change inside the thermosyphon. When the thermosyphon is subjected to the case of a large vibration-intensity parameter, boiling is suppressed due to the high requirement of superheat. Furthermore, as heat input into the thermosyphon increases, the effects of severe horizontal vibration on boiling suppression are annihilated.