Abstract
The purpose of this study is to clarify effects of micro-bubble injection on the heat transfer enhancement of natural convection along a vertical heated plate. We use thermocouples for the temperature measurement. We also use an image processing technique for obtaining the diameter of bubbles. The working fluid used is tap water, and hydrogen bubbles generated by electrolysis of the water are used as the micro-bubbles. The temperature measurements show that for all regions, the heat transfer enhancement is caused by the micro-bubble injection and that the maximum heat transfer gain with micro-bubble injection is approximately 24 when the bubble mean diameter and the bubble flow rate are, respectively, 50 μm and 39 mm^3/s.
