抄録
The present study has been conducted to make clear the mechanism that boiling heat transfer coefficient on a vertical heating surface decreases with decreasing clearance of flow channel less than 0.6mm. Liquid film attached to the heating surface under boiling bubbles and dry patches inside the liquid film were observed with a high speed video camera. The video image was taken from the backside of transparent heating surface made up of electrical conductive ITO coating glass plate. The heat transfer coefficient in flow boiling inside narrow channel may be closer connection with the area of dry patch than that of liquid film.
