Nucleate and Transition Boiling in a Narrow Space between Two Horizontal, Parallel Disk-Surfaces

Abstract

Nucleate and transition boiling within a space gap made by holding a ll-mm dia. glass disc in coaxial position above a heated ll-mm dia. horizontal, upward-facing copper disc has been studied experimentally for saturated water at atmospheric pressure. The distance between the glass disc and the heated surface s is changed within a range from s=∞ to s=0.1 mm, and high-speed photography is employed to record the behavior of liquid and vapor within the narrow space. It is clarified in the present study that, following the change of s, characteristic variations appear in the state of boiling, in the form of supply of liquid to the heated surface, and in the occurrence of burnout, respectively.