Numerical investigation of heat transfer performance and bubble behavior of nucleate pool boiling in a confined space under rolling conditions

Abstract

Nucleate pool boiling process is widely used in heat exchangers because of its excellent heat transfer performance. With the gradual increase of applications, more and more equipments work in a non-static state, but there is little research under rolling conditions. Therefore, it is necessary to investigate the influence of rolling motion on the nucleate pool boiling process. In this study, a numerical investigation of the nucleate pool boiling process under static and rolling conditions is performed based on the volume-of-fluid (VOF) method. Physical fields and phase distribution under static state and rolling motion are compared to investigate the effect of rolling motion on the nucleate pool boiling process. The results show that rolling motion greatly influences the bubble behavior and void fraction owing to the differences between flow fields. The void fraction decreased by 11.84%, 48.82%, and 56.87% as the maximum rolling angle increased from 15° to 45°, and by 11.84%, 22.27%, and 21.81% as the rolling period increased from 1 s to 3 s. The void fraction decreased by 11.84%, 48.82%, and 56.87% as the maximum rolling angle increased from 15° to 45°. The heat transfer coefficients of different cases are compared, and it is found that the effects of rolling motion on heat transfer coefficients can be ignored.

Keywords

• Nucleate pool boiling
• Rolling condition
• Bubble behavior
• Heat transfer characteristic