The Influence of the Bulk Liquid Thermal Boundary Layer on Saturated Nucleate Boiling

摘要

A physical model for vapor bubble growth in saturated nucleate boiling has been developed that includes both heat transfers through the liquid microlayer and that from the bulk superheated liquid surrounding the bubble. Both numerical and asymptotic solutions for the liquid temperature field surrounding a hemispherical bubble reveal the existence of an unsteady thermal boundary layer adjacent to the bubble dome. In addition, folding temperature profiles adjacent to the bubble dome are revealed. During the early stages of bubble growth, heat transfer to the bubble dome constitutes a substantial contribution to vapor bubble growth. The model is used to explain recent experimental observations of bubble growth and heat transfer on constant temperature microheaters reported by Yaddanapudi & Kim (2000). The good agreement between the model prediction and measured growth rate provides support for the current model.