An Experimental Investigation Nucleate Boiling in Thin Liquid Films.
Abstract
Experimental data was taken to determine the heat transfer coefficient during boiling of Freon 113 in thin liquid films from a horizontal, rectangular foil .025 mm thick. Heat flux was held constant at 8, 12, 16 and 32 thousand watts/sgm as liquid level was lowered from 18mm to 0.2mm below which dryout usually occurred. Surface temperature of the foil was qualitatively mapped with Cholesteric Liquid Crystals. This mapping was recorded and is presented by color photographs. There is an increase in heat transfer coefficient as liquid level is lowered below 2.0 mm for Freon 113. Liquid Crystals are a practical means of mapping the nucleation sites on the surface of a thin foil boiling test section. The heating surface under the bubbles forming on the surface is cooler than under the undisturbed liquid. As heat flux increases the number of active nucleation sites also increases. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1974
- Accession Number
- AD0780941
Entities
People
- Almon D. Rivers
Organizations
- United States Naval Research Laboratory