BUBBLE FORCES AND DETACHMENT MODELS

The forces acting on growing and sliding vapor bubbles associated with heterogeneous boiling are identified. Closed form expressions have been suggested which approximate the magnitude of these forces. Beginning with Newton's second law, a rational basis is proposed for predicting vapor bubble detachment diameters and sliding trajectories in heterogeneous boiling. Model closure is achieved without introducing arbitrary constants. The predicted detachment diameters and sliding trajectories are compared with extensive data for pool and flow boiling in both horizontal and vertical orientations. Good agreement is observed for all cases considered.