The influence of the bulk liquid thermal boundary layer on saturated nucleate boiling

A physical model for vapor bubble growth in saturated nucleate boiling has been developed that includes both heat transfer through the liquid microlayer and that from the bulk superheated liquid surrounding the bubble. Both asymptotic and numerical solutions for the liquid temperature field surrounding a hemispherical bubble reveal the existence of a thin unsteady thermal boundary layer adjacent to the bubble dome. During the early stages of bubble growth, heat transfer to the bubble dome through the unsteady thermal boundary layer constitutes a substantial contribution to vapor bubble growth. The model is used to elucidate recent experimental observations of bubble growth and heat transfer on constant temperature microheaters reported by Yaddanapudi and Kim [Multiphase Sci. Technol. 12(3–4) (2001) 47] and confirms that the heat transfer through the bubble dome can be a significant portion of the overall energy supply for the bubble growth.