Abstract
The transition process with which a liquid macrolayer of vapor mass structure from high heat flux to CHF was formed was examined from the image analysis and the behavior of bubble generation. As a result, vapor mass formation pattern exists in water, and the pattern decreases as it approaches CHF. On the other hand, vapor mass formation pattern of R141b is constant regardless of the change in the heat flux. Moreover, a liquid macrolayer of vapor mass structure in water has coalesced bubble. However, the vapor mass of R141b seemed to contact the heating surface, and vapor mass and coalesced bubble exist together on the heating surface.
