Effect of Wick Thickness on Maximum Capillary Pressure of Screen Wicks

The maximum capillary pressure of a screen wick is one of the most important factors to predict the heat transfer limit of the heat pipe in which a screen wick is installed. An analytical study on the geometry of the menisci formed in the space between the screen layers is conducted to define the effect of wick thickness on the maximum capillary pressure of a screen wick. An experimental study is also conducted to confirm the effect of wick thickness on the maximum capillary pressure using 8 kinds of a screen. The results show that the maximum capillary pressure of the screen wick increases with the decrease of wick thickness and the value reaches almost twice that of a case of a single layer screen. From the correlation between the analytical and the experimental results, a semi-empirical equation for predicting the maximum capillary pressure of the screen wick from the geometry of the screen, contact angle and the wick thickness is derived.