| Abstrak/Abstract |
As elaborated by Mudawar [1], cooling technologies for electronic devices have shifted from natural convection to single-phase forced convection and then to phase change cooling systems. The heat transfer performance limitations of natural and single-phase forced convection have driven the development of two-phase cooling or boiling heat transfer. Hence, two-phase cooling is generally considered to be one of the promising techniques for high heat flux electronic devices in the future.
The bubble departure diameter (Db) and frequency (f d ) are important parameters in bubble dynamics that directly affect boiling heat transfer performance. Surface heating, liquid heating, nucleation, bubble growth and departure occur continuously and repeatedly during the boiling process such that the cycle is normally known as an ebullition cycle. During the boiling process, a bubble is generated from an activated
cavity on the boiling surface. The generated bubble grows during the bubble growth time and then departs from the nucleation cavity. The bubble diameter at the time of departure from the nucleation site is called the bubble departure diameter. The bubble departure frequency indicates how fast the bubble grows and departs from the cavity. It is affected directly by the bubble departure diameter. At the same heat flux, a smaller bubble departure diameter will result in a higher bubble departure frequency. |
