2006 Volume 49 Issue 2 Pages 318-325
Boiling CHF was assumed to happen based on hydrodynamic instability, and the value was thought to be unaffected by the surface condition of heater so far. However, it has been understood that the CHF value changes systematically depending on experimental conditions according to a series of experiment of the authors. As the reason, it is assumed that CHF occurs based on heterogeneous spontaneous nucleation (HSN). Especially, it appears remarkably in transient boil CHF. Moreover, it is thought that HSN physically influences the surface condition. In this study, the transient pool boiling CHF for exponential heat generation rates with various periods for saturated and subcooled liquids at various pressures were investigated to clarify the effects of surface conditions such as commercially-available and roughly-finished surface cylinders in water, ethanol and FC-72. It was clarified that the trend of CHF for the shorter periods was significantly affected by the surface conditions.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering