Consideration of Minute Unevenness (2nd report) Creation Method and Inspection of the Surface Function

—Boiling Heat Transfer by the Difference in Shape Parameter and Array Pattern of Dimple Texture—

Abstract

The purpose of this study is the proposition of a high efficient processing method of a dimple texture to promote boiling with low superheat. And, we produce a system evaluating a nuclear boiling start of the dimple texture. Using these, we compare the start of nucleate boiling and the behavior of bubbles under the condition that the aspect ratio and the contact angle of the surface are changed according to the shape parameter of the dimple. At least the aspect ratio of 0.1 is necessary for the dimple to improve the heat transfer performance of the surface. In addition, by changing the arrangement of the dimples and imparting a gradient of the contact angle, heat transfer performance is improved.