Vapor bubble growth and model assessment in saturated pool boiling of water across a wide range of pressures

The growth of vapor bubbles is a complex, rapid, and elusive phenomenon involving multiple heat transfer mechanisms, such as heat conduction, microlayer evaporation, and boundary layer evaporation. To improve the understanding of the bubble growth process, this study conducted saturated pool boiling experiments under atmospheric pressure, characterizing both the bubble growth dynamics and its stochastic nature. Then, a comprehensive dataset for heterogeneous pool boiling was established by incorporating 10 additional experiments, resulting in more than 2000 data points spanning a broad range of conditions: pressures from 0.001 24 MPa to 9.57 MPa, wall superheats between 1.6 and 40 K, Jakob numbers ranging from 0.092 to 2808, and Prandtl numbers from 0.83 to 9.4. Notably, this pressure range represents the broadest range considered in the analysis of bubble growth rates, to the author's knowledge. Subsequently, a systematic evaluation of 16 existing bubble growth models and correlations—including bubble layer-based models, microlayer-based models, and empirical correlations—was performed, providing valuable insights into the dominant heat transfer mechanisms at varying pressure ranges. Finally, a new recommendation for the bubble growth rate under a wide range of conditions was provided. Specifically, Cole's correlation was recommended for Jakob numbers below 200. For Jakob numbers exceeding 200, a new correlation was proposed. The new recommendation demonstrated high accuracy in predicting both the bubble growth rate and departure diameter, with an average error of 34.3% and 32.4%, respectively.