In boiling heat transfer, a large heat flux can be obtained from a small temperature difference between the heat transfer surface and the cooling water, enabling efficient cooling of the heat transfer surface. In this study, in addition to the needle-shaped microstructures and cavity-shaped microstructures used in the authors’ previous studies, needle-shaped microstructures with a larger structure height were used to compare heat flux with smooth surfaces. Furthermore, the two types of needle-shaped microstructures were applied to the inner surface of the tube, and their heat transfer enhancement effects were investigated by comparing them with the smooth surface. Using an evaluation method based on heat transfer coefficient, the advantages of the microstructured surfaces and the effects of structural differences were clarified.
Onodera et al. (Wed,) studied this question.