One of the most promising cooling methods for high-heat flux applications is boiling, but is notoriously difficult to predict in a universal, mechanistic way (Dhir, 2006). Despite several decades of work, even bubble growth and departure prediction is still far from satisfactory. As a major step towards this prediction, the dynamics of a single bubble (non-interaction bubble regime) have recently been successfully modeled by the authors by relying on a 1D energy and global force balance (similar to Zeng et al., 1993). This model, originally developed from the droplet-boiling case, applies under the limitation that boiling is sufficiently dynamic that radial convection dominates the bubble heat transfer (the RCD model), thereby it is valid above a superheat threshold (Stephan number>2.5%). The present study extends this model by examining the dependence of departure and growth on gravity. Previous studies have found dependencies ranging from to , with typical values around ⅓ (Di Marco Grassi, 2009) the value suggested by the present model. Recent literature is reexamined only within the buoyancy dominated regime (described in Raj, 2012) and good agreement with a value of is found, rather than the suggested dependence. Furthermore, the present model reveals that bubble growth curves characterized by n=, will have no gravity dependence, and only the bubble growth duration (departure diameter) will be dependent on it, as verified by experimental literature (Siegel & Keshock, 1964). This model has also been extended to the high pressures (0.1-17MPa) relevant to many applications. Similarly to previous findings (Jensen Memmel, 1986), it is seen that a single power-law description for pressure dependence, as used at atmospheric and sub-atmospheric cases, is not sufficient over the entire range. A new alternative pressure-dependence is presented and physically explained, which successfully predicts the entire range with a single equation.
