On the vertical size of two-phase pool boiling structures

In a previous publication, the authors identified that the two-phase boiling structure arising from a boiling surface exhibits periodic behavior over time. This new research constitutes a step forward, as it reports and characterizes the vertical size of the boiling structure. The experimental data used comprehends a boiling curve of saturated HFE-7100 at 100 kPa with a polished copper surface. The comparison between the width signal and the two-phase structure videos revealed that the vertical size of the sub-structures is related to the wavelengths of the function that provides the whole boiling structure. This manuscript shows that larger structures are related to larger wavelengths of the function. This analysis also proves that all wavelengths (bubbles vertical sizes) are present inside the two-phase structure. An outstanding finding of this research is the linear relationship between the position of the structure center when it first appears, y , and the wavelength associated with this structure, λ . This relation is y = 0.75 λ . The present paper brings forth new insights into the periodic nature of the two-phase boiling structure from a spatial point of view. This approach constitutes an additional and relevant insight on boiling phenomena.