Abstract
A model considering evaporator wettability in terms of the contact angle is developed in this study. In addition, experiments are conducted using a copper thermosyphon with a length of 240 mm and internal and external diameters of 22.2 mm and 25.4 mm. The influences of the inclination angle and evaporator wettability on the heat performance of a thermosyphon charged with water are investigated. It is observed that simulated temperatures agree well with experimental data with a relative error of 0.12% for a modified thermosyphon. The results show that bubbles attaching to the wall of the evaporator decrease as the inclination angle increases from 15° to 90°, which decreases thermal resistance by 59.5%. As the heating power increases from 10 W to 14 W, thermal resistance reduces more significantly (44.1% decrease) for an evaporator with a hydrophilic surface than for an evaporator with a hydrophobic surface (20.6% decrease) because the bubble emission frequency of a hydrophilic surface rises more sharply (265% increase) than that of a hydrophobic surface (100% increase) at an inclination angle of 90°.
Original language | English |
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Pages (from-to) | 675-684 |
Number of pages | 10 |
Journal | International Journal of Heat and Mass Transfer |
Volume | 116 |
DOIs | |
State | Published - 1 Jan 2018 |
Keywords
- Bubble emission frequency
- Contact angle
- Evaporator wettability
- Fluent CFD modelling
- Inclination angle
- Thermosyphon