A PHOTOGRAPHIC INVESTIGATION OF BUBBLE NUCLEATION CHARACTERISTICS.
NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF
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The characteristics of bubble nucleation, growth, and departure during nucleate boiling were investigated. The liquid-vapor interface motion was analyzed using high speed motion picture photography. The fluids used were distilled water, water with wetting agent, water with sucrose, ethanol, and freon-11. Cylindrical, conical, and reentrant cavity geometries were employed in addition to J, L, and I shaped capillaries. Cavity inner diameters were fixed at 0.085 centimeters and cavity depth ranged from 0.230 to 0.703 centimeters. Consistent results were obtained for geometrically similar cavities and for the same cavity at different occasions. A thin liquid film was observed on the cavity inner wall which was directly related to cavity nucleation stability. The liquid-vapor interface penetration was shown to be dependent upon cavity geometry and fluid properties. Frequency, but not penetration, was affected by heat flux and superheat. Author
- Fluid Mechanics