Effects of continuous wettability on the pool-boiling bubble dynamics and heat transfer characteristics of a triangular structure-roughened surface

A phase transition lattice Boltzmann model is used in the current study to simulate the pool boiling process on a triangular structure-roughened surface with conjugate heat transfer effect. Through the verification of the Laplace law and the theoretical film boiling results, the adopted model is ensured to predict pool boiling phenomena accurately with excellent stability. The bubble dynamics, including the nucleation, growth, coalescence and detachment of the bubbles on the triangular structure-roughened surface with continuous wettability, is discussed. Little research has been conducted on the continuous wettability effect on the pool boiling with triangular structures-roughened surfaces. The results show that a hydrophilic surface inhibits bubble growth but facilities bubble detachment with bubble nucleation at the concave corners; a hydrophobic surface increases bubble growth but inhibits bubble detachment with bubble nucleation at hydrophobic areas. It is found that when the direction of the self-drive favors bubble detachment from the surface, the surface which from contact angle theta (Bottom) = 120 (degrees) to theta (Top) = 90 (degrees) under the study can achieve better heat transfer over a wider range of superheat, while setting the continuous wettability from theta (Bottom) = 120 (degrees) to theta (Top) = 60 (degrees) can achieve a better heat flux density at lower superheat.

Automated summary

A phase transition lattice Boltzmann model was used to simulate the pool boiling process on a triangular structure-roughened surface with conjugate heat transfer effect. The results showed that a hydrophilic surface inhibits bubble growth but facilitates bubble detachment, while a hydrophobic surface increases bubble growth but inhibits bubble detachment. The study also found that continuous wettability can improve the surface's heat transfer performance.