A Theoretical model to predict pool boiling CHF incorporating effects of contact angle and orientation
Abstract
A theoretical model is developed to describe the hydrodynamic behavior of the vaporliquid
interface of a bubble at the heater surface leading to the initiation of critical heat
flux (CHF) condition. The momentum flux resulting from evaporation at the bubble base
is identified to be an important parameter. A model based on theoretical considerations is
developed for upward-facing surfaces with orientations of 0° (horizontal) to 90°
(vertical). It includes the surface-liquid interaction effects through the dynamic receding
contact angle. The CHF in pool boiling for water, refrigerants and cryogenic liquids is
correctly predicted by the model, and the parametric trends of CHF with dynamic
receding contact angle and subcooling are also well represented.